135 guy here with a ton of friends at 121 (that call me weekly complaining about their jobs) so take this for what it's worth as a neutral party on the outside looking in.

If you have literally no obligations and can move anywhere and your only goal is to get in and get out as quickly as possible, I'd seriously look into Mesa. I have 2 close friends there that both upgraded at their SDF base in just over 12 months after they completed IOE as an FO. Both also held a line their month as CA and are crediting 80+ hours a month now. As an FO they spent almost no time on reserve (maybe a month after IOE) and broke min guarantee almost every month with 16+ days off. Also picked up a few extra trips for 300% pay. For what it's worth, they both upgraded significantly quicker and made quite a bit more money than several other friends I have that entered the 121 world around the same time at other "more respected" regionals. Most of them had only been off reserve for just a couple months when my friends at Mesa were upgrading. They were both in the same boat as you. Single, no kids, could move anywhere and just wanted to get in get their time and GTFO.

Definitely not a place I'd want to get stuck at if the music stops, and obviously bases can close and airlines can lose flying to other carriers which can halt things, but I'd definitely at least take a look at them. DM me if you want and I can try and put you in contact with my friends there, they'd probably have more detailed info if you want.