I think that the fact that you are asking this question means you are already asking if it's worth it to climb from 4k-5k.

It's very difficult and not worth it to climb from 4k-5k honestly. If you are a good player your winrate will be about 52-55% (may be higher if you spam support like shaman/omniknight just to win), you can calculate from there how many games you need to win and climb MMR. Unless you are good enough and you want to go become professional dota 2 player like MidOne/Mushi, it's just a waste of time.

From personal experience, I reach divine 0 (just under 5k) and then I gave up, too many smurf/booster/acc buyer and ppl who don't play serious for ranked. I realised I was wasting too much time trying hard for ranked, there's no point because MMR counts for NOTHING in real life. Your real life suffer also because you play too much Dota, even though you don't like thinking about it. Also playing solo queue in SEA server makes you want to uninstall, like you said first pick carry gaming, farming gaming, worst of all you pick support but that first pick invoker/SF/antimage is fucking noob and you have to support him.

TL,DR: Don't bother, just uninstall the game because it's a waste of time. Dota 2 is dying game anyway, in 2016 there was 700k avg players, now only 400k players and dropping every month.