Realise that there is no "your" thought. First of all, the language you acquire as a child, for years, indebts you deeply to society. The things you can think are limited by the language delivered to you by society. If you are a so-called "creative" then you'll probably add a few words or ideas to that corpus, maybe you'll "re-organize" or "re-order" it a bit. That is an exception though. The idea of purely independent thought is an illusion. It follows that independent action is also an illusion (your idea of what to do next, as well, tends to be borrowed!) Thought is moving through mind to mind, and it has its own existence, its own nature.

1. All thought is fantasy

2. Some of that fantasy happens to pass the test of reality

3. Most thought is borrowed

4. Thought existed before you, will exist after you

5. Society is the manager of thought, not the individual

6. Thought advances as a whole

7. Without collective thought as a substrate, the individual won't function

mimetic theory is an interesting lens to look through for that question. Rene Girard in particular sheds some light on this - it's quite compelling (lifted from wikipedia):

The name of the theory derives from the philosophical concept mimesis, which carries a wide range of meanings. In mimetic theory, mimesis refers to human desire, which Girard thought was not linear but the product of a mimetic process in which people imitate models who endow objects with value. Girard called this phenomenon "mimetic desire", and described mimetic desire as the foundation of his theory:

    "Man is the creature who does not know what to desire, and he turns to others in order to make up his mind. We desire what others desire because we imitate their desires."
I am a fan of do some then learn some.

For example, in the simpler case of pure technology. Try building in React and only then do the React course. You’ll come with the confusion and questions and know what to get out of it.

In business it is trickier because the amount of poor information out there is ridiculous. Even good information can be bad if it is bad for you specifically. As people often way overconfidently propose they have cracked the code to making money.

Which is ridiculous.

It is easy to see how silly it is if you reframed that in terms of employment. “The secret to $200k/y. Our blueprint shows you how to make $200k/y as a medical doctor…”. What if you hate being a doctor or are no good at the various innate skills needed!

A big part of the answer is that many people have a fear of looking stupid or having their ego shattered. You're probably not going to be laughed at for trying to do what others have already tried and that society accepts, but you risk being laughed at for trying some unique new marketing idea you came up with.

Another part of the answer is that very few people are experts at all of the skills needed to start a business: being a domain expert in some field, understanding technology, understanding business and money, understanding people, being good at communicating, understanding design, being a good writer, etc. If you're smart, you know that you don't know everything, and you're willing to hear out the advice that others provide.

We want to see the path before we walk on it. Sometimes it gives a new perspective we wouldn't come to on our own, other times it's a big distraction that feels like progress. I am an advocate of doing it yourself as far as you can and learn learn learn from your mistakes. The same bit of advice can be disastrous for one person and a game-changer for someone else, so you might as well try your intuition for problem-solving first and then see where you get stuck.
Everybody has their own opinion

I agree.

The important thing is some people have informed opinions on topic X.

Most people don’t have an informed opinion on topic X.

Where topic X is not a topic where all opinions are equal, e.g. who should be elected to office Y, the appropriate role of religious practice, and what is sexy.

Starting is not incompatible with valuing informed opinions.

Sure finding informed opinions can be hard without experience in topic X. But learning to identify uninformed opinions is straightforward work.

Good luck.

Innovation is not something we do in isolation. We build on the work of others. That means we need to study what others have tried. Your contribution will be layered on top of the work they have done. It can be tricky to both put yourself in the shoes of another in order to understand their work, concerns, and motivations while maintaining space for one's own ideas, approaches, and goals.
I was looking at something I thought I could use the other day, and I was so disappointed in the really awful API which made it unusable. So I took a look into the code ... it was majestic! Someone had way more time and ability to code the thing than they had ever put into considering whether it was usable or not.

Make stuff that works first.

It depends on what you are building, why, and frankly whether you have the potential to provide something both novel and useful.

But, yes, I would say sometimes it’s beneficial to not only ignore, but also to not even know how others before you have solved a similar problem. Pathways established in our minds are obstacles to invention.

The "learn form your own mistakes" phase must occur at some point, regardless.

You may or may not be capable of learning from the mistakes of others; which is the prime reason for listening to others. The other reason is gathering ideas for things to do; and it sounds like you've already got that covered.

If you learn from others you save yourself a lot of time. Imagine if you had to invent all of mathematics yourself. I think learning from your own experience is best but there is just not enough time to always do it.
society and culture are conformity, so to live in a society and/or culture and have some kind of influence or impact, you need to provide some kind of value that others deem as "good." We don't live in a bubble.
Human insecurities and fear keep the windmills turning and generating electricity!
Speak for yourself.