if you are 21 y.o. vlogger focused on barbell training and restoring old american muscle cars, this advice will sound like "dude just do more straight deadlifts and focus on hi-rep kroc rows, they will help you with development of your back" -- aka, some special gibberish speak. it takes so much knowledge to do so, it just won't happen.
Sometimes, they don't want to.
Sometimes, they would rather not.
Sometimes, they would rather pay more money or spend less effort.
I would guess that your hypothetical vlogger is likely to just open a Youtube channel and pray, and they will get results consistent with that. It's not a business plan, and they didn't ask my advice.
If you see a business opportunity in making these things comprehensible or easier or more affordable to vloggers, you should go ahead and do that.