I recently launched some macOS Shortcuts in Lunar (https://lunar.fyi/#shortcuts) that can arrange monitors in pre-defined layouts like:
2 Screens Vertically ■̳̲
2 Screens Horizontally ⫍⃮݄⫎⃯
4 Screens in a 3-above-1 configuration ⫍⃮■̳̻⫎⃯
3 Screens in a 2-above-1 configuration ⫍‗⫎
3 Screens Horizontally ⫍⃮▬̲⫎⃯
It's not the same as DisplayPlacer but for a lot of people this could be enough. They are free and can be used without a Lunar Pro license.
For those having trouble with monitors being swapped around by the OS, there's also a Swap screen positions action in Shortcuts that you can bind to a hotkey to quickly fix this. It even swaps rotations, which is especially useful for those using portrait monitors (one at 90° and one at 270°).
Currently using displayplacer with BTT to make keyboard shortcuts.
When moving to different hoteling desks, sometimes the laptop is on the left of the additional monitor and other times on the right. Now I have two keybinds that orient my layout. I've used Lunar specifically for the dim below 0 functionality, (thanks for the ongoing development), I'll have to try the new shortcuts to see if they can replace displayplacer.
For those having trouble with monitors being swapped around by the OS, there's also a Swap screen positions action in Shortcuts that you can bind to a hotkey to quickly fix this. It even swaps rotations, which is especially useful for those using portrait monitors (one at 90° and one at 270°).