I'm new to the sport. But I've ridden BMX for a long time and am a pretty good rider. The consensus over there for the most part is that a more expensive part will not make you a better rider, it will just be more bulletproof/less susceptible to breaking.
When it comes to MTB I'm getting some golf like vibes. To where a lot of the people who are fanatics about it are people a little outside of their physical prime (much less so than golf, but relevant.) I bring this up because in golf, it's a big thing to where you can get really expensive clubs to fit you and make you a better golfer. They can monitor your swing and tweak your clubs to correct for issues with your form. So instead of getting better at golfing, your clubs will make those corrections for you if you're willing to open your wallet.
Now I know MTB isn't exactly like that. People know that a better bike won't make you a better rider for the most part. But people are out here suggesting bikes that are way too expensive for seemingly no reason. As mentioned, I'm a very competent BMX rider and have seen posts stating that $1000 hard tails just aren't good enough. I found a friend with a Diamondback Sync'r who was willing to let me borrow it for a day at the local bike park recently (I'm in the market for that tier of bike, if not that specific model.) I saw a ton of people riding like $4,000 full suspension bikes who could barely bunnyhop. Looked uncomfortable pumping rollers and overall just looked like they had a long way to go to get where they want to be.
I'm starting to get the feeling that a lot of people on this sub and in the sport as a whole have read that you need this or that spec, to hit this dollar amount or have this new tech in order for a bike to be good. I feel a lot of that may be regurgetated information they've read and have repeated themselves without any personal experience of opinion as to why these things are truly good in the real world. But most importantly, I'm learning that a lot of people on the internet adore the sport and have invested HEAVILY into a bike that quite frankly, is well above their skill level. Obviously that is not really a bad thing. Having too much bike for your riding means it will essentially last forever so long as it's maintained well. But if people use that as a basis of what a good bike is, at their specific riding skill level, it just skews things way out of whack.
I asked on this very sub if a Marin San Quentin 1 was a good bike basically. Got some responses saying that I should skip it and keep looking because it didn't match what people thought the spec sheet should look like. Now if you go on YouTube, you can see Matt Jones (the dude who had a heavy hand in designing that very bike) just destroying Whistler with that exact base model hard tail. Granted, he is one of the best in the world. But the fact that an entry level bike can handle the abuse such a talented rider can throw at it on one of the most desirable trails in the world without a hitch proves it is a very capable bike. Yet on Reddit, people say I should keep looking because it doesn't have a rear through axle.
You just need to take what people say with a grain of salt. I have absolutely zero doubt that there are thousands of people commenting on this very sub every week with $3k - $6k bikes, telling people they need to spend more to get into mountain biking who would struggle to hit an 8 foot double jump. It's good to tell people what to look for so they don't buy a shit bike and have a bad first experience with mountain biking. It's a whole different thing to upsell people and say $1000 USD isn't enough to buy a bike to learn to ride trails.