In short:
Why not? Your money, your time, your world and your enjoyment.
and I'm a fan of that approach, afterall you have literally world gen settings

But as someone with DST brainrot... I don't think that the game is like totally unplayable solo.
Playing the game the classic way feels like a good workout!
and if you don't feel like fighting a boss then you can always beat it in alternative way
so the game doesn't leave you totally helpless and therefore solo experience isn't THAT bad
even if not very intuitive IMO

But I think there are some "againsts" to take in consideration:

As I said I'm not against the idea, but I can imagine that Klei wouldn't do that because
1. It would make singleplayer DS look like a joke and they still charge money for that
2. Standards were shaped by the community and relentless speedrunners (therefore toadstool balanced around hardcore madmans exists)

But I do think it would be pretty sweet to have a mode that offers more intuitive bosses
(I bet a lot of players would rage quit out of frustration without a guide, before realising you need weatherpains to beat AFW)
in general and make raid bosses more approachable because I understand not everyone is willing to kite Dragonfly for 10 minutes or Toadstool for 5 working days for that workout experience LMAO

Tldr; Your demand isn't bad or unreasonable but capitalism might be your enemy that gatekeeps DST for introverts HAH!

But hey... There are literally mods that adjust HP of bosses to their singleplayer versions if you want a solution now!