I agree, for the most part. Yes, the internet has given Yer Avridge Homebrewer access to a greater amount of knowledge than I imagined in my wildest dreams when I started in the early 1990s. It took me ten years to amass the kind of knowledge a new brewer can now amass in a weekend.
However - here is where I do not agree - knowledge does not equate with experience. You can read up on yeast all you like, but you still will have no idea how it will actually behave in your brewery until you use it. If you have an extremely well-equipped home brewery with temperature control and yeast-harvesting/building equipment, you have a much greater measure of control, and I will agree with you 100%. But the majority of brewers don't have that. Yeast/ferment management is beyond the skill and scope of most hobbyist brewers and breweries except in the most rudimentary of ways.
Selecting a handful of yeasts to use all the time lets the brewer learn how to maximize consistency and excellence under those circumstances. I use three yeasts - three - to brew everything I brew. I can actually RDWHAHB, because I know how each will perform at any given time in my brewery. They're like old friends.
Puddlethumper, I stress strongly in my fevered jottings here on HBT and elsewhere how sound an idea is keeping it very basic in the beginning.
It's like brewing in a brewpub. A pub-brewer has a "stable" of standard house beers. Generally speaking, you have "training wheels", Amber, Brown, and Dark. All of these the pub-brewer must be able to brew consistently to excellence without blinking. Then you have a rotating tap or three of stuff which lets you play, stretch your legs, expand your scope. Brewing the "stable" day in, day out lets you build XP to a point where you're high enough level to actually approach Imperial Pumpkin Raspberry Belgian Sour IPA with a reasonable assurance of success.
Let's say you take my advice and pick four good recipes from the HBT archive: Light, Amber, Brown, Dark. You brew them until you know them inside and out. You know what they're supposed to taste like. You've been brewing an all-malt Blonde as your "Light", and really enjoy it. Now let's say you get the itch to brew a Belgian Blonde. Your experience brewing your Blonde means you can simply switch the yeast. You have enough XP that you don't really need to worry about anything other than making a new yeast strain work.
See what I mean? It's a method of reducing variables and worry so that you can be more assured of success. Too many brewers want to jump right in with the Imperial Pumpkin Raspberry Belgian Sour IPA, not realizing it can take
years of adventuring to gain enough XP to level up to where you can cast that spell. You need to learn Magic Missle before you can learn Fireball.
Okay, enough full-frontal nerdity in the metaphors. You probably get the picture now.
Bob