While I disagree that people would stop using Yellow Trinket entirely (that didn't happen when purchaseable wards and trinkets coexisted), I agree with the rest of the criticism. As desirable as wards are right now, historically they've always created this huge discrepancy between standard and pro play, because of the sheer difference in the number of wards that get bought and used by teams. Wards are innately useful (and in fact extremely powerful), but not innately fun, nor do they even convey properly how useful they are to the unitiated, which is why they're so unpopular even in an environment where wards are literally free. I do think we could do with some more vision on the map right now, but I don't think buying wards are the best way to go about doing that.
I think part of the problem right now isn't simply the lack of vision in League, but how the game largely punishes people for not using vision even when there's nothing more one could've done. Facechecking the brush was notoriously dangerous even before damage in the game crept up to current values, and right now we're at a point where it's impossible to not facecheck, which leads into plenty of situations where champions get ambushed and killed with little they could've done to change the matter. Effectively, League is still stuck in a mentality where players who use insufficient vision get punished hard, even harder than before, but its environment has changed to a point where both teams always have insufficient vision, no matter how well they ward. Toning down this punishment to give players more of a chance when they get ambushed (which might require toning down damage in the game overall) could itself go a long ways towards making the lack of vision feel less harsh.