Max out Machamp?

Machamp is the most useful attacker for gyms and is great for Ttar and Absol raids. If you are going to max out anyone, he’s got to be a top candidate. I’ve maxed out three. What else are you going to do with your dust?

Cool. So, keep doing weather boosted Champ raids until June and then max this one if he's still the best.

If you fight gyms a lot and tend to see big Blisseys, its worth taking your Machamp to at least level 36,5. That's the breakpoint for 15atk Counter against a maxed 15def Blissey and there's a noticeable difference in reaching it. I would advocate against going all the way to max until you get all your best meta mons to 30+. Maxing out starts to make sense after that point.

It's THE gym attacker, so well worth powering up even if it's not the top raid counter right now. Barring major balance reworks, Machamp will stay the top fighting type over gen 4, which also makes it the top counter to Dialga, which is a lot more valuable than countering the Regis.

EDIT: I would appreciate a comment to accompany downvotes, I don't really see what part of my advice is wrong. The Machamp vs. Blissey breakpoint is a fact and is the best power up target if one is optimizing their resource usage. It's also a fact that gen 4 does not have any fighting types that could challenge Machamp in the current system.