You’ll get a whole lot of responses on the schools of thought about recovery and recovery tactics.
Personally, I just lightly stretch my whole body at the end of the day and do some yoga. Yeah I have doms daily, but you get used to it and can sense and feel different levels of working within doms and still growing.
DOMS is your body’s way of telling you it’s recovering. You can push doms to an extent but your performance will suffer if you don’t listen to your body. It’s a delicate balance of pushing and adapting. You want to be in or near functional Overreaching to obtain the best growth and results. That’s different for every person in here because our levels of adaptability and thresholds for working within fatigue are so unique and personal. It all equates to TSB CTL, and ATL.
Do you need a massage gun? IMO, no. Percussive therapy is hitting already fatigued and micro torn muscles and is arguably injecting more trauma through high frequency vibrations into the muscle fibers possibly exacerbating the micro tears in the muscles. Will it increase blood flow, yes. Could that then hasten recovery, possibly. But your body is already keyed and programmed to do that on its own if you’re eating the right macro balance for the workloads you’re doing. I find that if my DOMS is really bad it’s also a sign of not being properly hydrated. The better hydration, the less DOMS I experience and I switch stuff up quite a bit.