Do you mean L44->45 tasks? Beat 100 grunts, 50 leaders? Or the 43->44 30 battles per league +20GBL?
The latter are easy, especially with an alt as you can just 10cp mon it in seconds for the 3 leagues then just throw the same 10cp mons into 20 GBL battles.
The former, the rocket battles, are a pain if you don’t do them usually but are there to make you try them. Just like all the various GBL related tasks and rewards that I used to hate until I got more into PvP.
Rockets pay 500 dust each, plus a chance of a decent shadow. The leaders pay 1000 dust, plus a shadow sneasel with shiny chance if you stick to Sierra. Then you get a 12k egg that’s worth good dust and a chance for rare pokemon and xl candy. It might not be enjoyable but it’s certainly at least paying you back well enough.
If you truly hate them, just pick the easy ones, they’re all easy (can’t recall when I last lost to a shadow) but some are walkover, the fighting one is really easy with M2.
You’ve got to do it once, the L46 tasks are really easy, so even if it takes you twice as long, you’ll do it eventually. Failing that, L50 means bugger all anyway, so if you don’t want to do it, you don’t have to.