There are some mangas that seem to make progress like crazy and yet others that seem to make no progress at all...
D.Gray-man seemed like it was making progress but then in the last chapter it turns out everyone can just be brought back to life. When one Noah dies the memories are reborn in someone else.
Berserk... goes without saying. In 20 years it still doesn't look like it's closing in on anything. The last chapter gave some hint that maybe now it's POSSIBLE to fight the God Hands and maybe they're getting close to the elf place they were heading toward. And the current hiatus ends in I think 2 weeks.
One Piece on the other hand DOES make progress since now they're finally at the half way point, there are certain people who have been talked about that show up over time, mysteries are uncovered, etc.
Naruto it's been stated is almost done. The progress with that is more or less just when more enemies are defeated.
Kochikame started in 1976. The next oldest manga in Jump is One Piece which started in 1997... And it's been said he doesn't ever plan to end it...
FMA is ending soon. That, too didn't seem to make "clear progress" for a while. Though they did start to uncover mysteries and just recently started to defeat the Homunculi.
Gantz is in the "Final Phase" when it restarts in a month or so. So... It's what... 2/3 done... I forget which was the previous phase. I checked, it's 2. So 1/3, which could be longer, shorter... or whatever. So far it's been about 300 chapters so at least another 2 years.
Bleach, who knows. It could end with Aizen or it could keep going after that somehow or other.