Ehhh ... I don't think it's more of a waste of time than actually playing the games themselves.
The only times I really question it are where I'm just following a guide to platinum a game without any thought - which I did for a few trashy PS+ visual novels late last year - although in my defence there, I didn't pay for them, and I found the Zero Escape series via that. The other time is where money is involved. Games simply seeming to
exist for the purpose of platinums (clicker games, "bad" games, puzzle games with absurdly easy solutions), games releasing without global lists to encourage rebuying
for the first person who says it, Demon's Souls DOESN'T count here .. I feel that's potentially exploitative. And that time I platinumed the DMC2 HD remaster ... that one almost broke me.
In general, I enjoy going after trophies because they give me a bit more value out of the games that I own - different things to try and do. Doesn't help the backlog though ... not many of the games fall into the following categories, but the ones that do definitely have an impact.
I might see parts of the game that otherwise, I wouldn't have seen. Eg - I played Disgaea 1 and 2 on the PS2. Completed the plot (in D1's case, replayed for the good ending), then put them down and haven't touched them since. For Disgaea 3 on the PS3, I waited for the trophy patch, platinumed it, and in the process discovered that these games have an incredible postgame treadmill. Not sure if it was an enjoyable treadmill, mind - but it's still something I wouldn't have seen otherwise.
They can help change or solidify opinions about games. Eg - Bayonetta. I played through that, and thought the game wasn't all that good. Bad camera, bad lag, game didn't feel right, stupid bullshit QTEs. But hearing all the praise for this game encouraged me to keep going, give it some more time, and it'd turn out good. So I kept my bad opinion to myself, sort-of Got Gud (it doesn't require an extreme level of Git Gud, but enough to pass the challenge levels / Alfheim Portals and whatnot), platinumed the game, and unlocked some optional stuff on top of that by platinuming / pure platinuming each chapter. And you know what? My opinion is now ahahhahahaaha NOPE it's still trash and Nintendo can have the sequels for all I care - and that plat helps give me a bit of confidence in that opinion.
I also like to speedrun trophies sometimes - mostly adventure games. Eg - Day of the Tentacle. I played that game to death in the 90s, and getting it free on PS+, I could've burned through it in an afternoon. I did that ... on a burner account, then wrote my own walkthrough for the game, practiced it a few times on other local users, revised the route, trying to get my time as low as possible, then executed (and succeeded) on my main account with some definite room for improvement. The time shown was just over an hour, but the prep time was significantly longer than I otherwise would've played there. And as far as main accounts are concerned, you get one shot at it. That time is a permanent mark on my account that can't be changed. Like a Hitman elusive target without an XMB force quit to reset it if things go south. I think it's an interesting enough challenge, anyway.
The response to all of the above could be "fuck me, that's a lot of justification for meaningless objects" and you'd be absolutely correct. I don't know. I just don't think it's any more of a waste of time than playing the silly games in the first place ¯\_(ツ)_/¯
I feel you. I'm most bothered by platinuming Sound Shapes on the PS4 (just the core game, none of the DLC), then downloading the PS3 version, booting it up, syncing the cross save, and watching another plat pop. Didn't feel good. Didn't stop me from doing it years later when the Vita rocked up though D:
Anyway ... actual stuff now ... Platinum #265 - Sniper Elite 4
Eh. I don't know what I was expecting here. I think more of a simulation rather than a generic-ish 3rd person shooter? It's alright, but really nothing to write home about. The levels are too long for their own good, the MP trophies were just annoying, and following a collectible list (which is mandatory because they're not easily labelled) takes a lot out of the first playthrough.
Authentic was alright though. PROTIP: don't start on Authentic. Just ... DON'T.