Currently have a dell 27" 1440p 144hz IPS monitor which I really like.
Will going for one of those LG 32" panels not look as good (pixel density)?
It won't, but according to Monitors Unboxed, upscaling tech like DLSS and FSR will help with that, it can also help to set the monitor a little further back. It doesn't seem like 1440p @ 32" is a massive issue, but as I haven't seen it for myself I can't be sure, 27" is definitely the sweet spot for 1440p, 32" is ideal for 4K. Obviously you need more GPU to power 4K.
I was thinking about getting a 32" 1440p, but as I already have 27" 1440p, that didn't seem a worthwhile upgrade so I have decided to go for 4K.
I think with upscaling and tinkering with settings you should be able to get a good experience at 1440p and 4K at 32" if you're prepared to be realistic with 4K - of course this is very dependent on what GPU you have.