Not happy with Electrical Wiring

[halfmoonforever]

Just about every socket I've ever opened has had something like that done in it.
Hell, until recently wires were joined with these:
View attachment 421264
and probably still are.

If only they were joined like that :/

My one new light switch failed the other day, not sure if there was a spike or something, contacted the company for a replacement, but they don't have stock. Was thinking of soldering these wires together myself to make sure the connection is more solid, but rewiring is still on my mind, especially since I want to do some work on the bathroom, might as well lump everything together if I can