Completely depends on the Game.
Some games, yes it make a big difference going from a mechanical HDD to a SSD, others not so much.
Example:
If you play Open World games where there is no loading screens then no.
The game buffers as you move, so SSD's really have no impact over a mechanical HDD.
If you play a game with map transitions and loading screens, then yes.
The map will load faster as its buffering to memory.
If you play ForteNite, PUBG, CoD, BF, CounterStrike, then absolutely NO.
There are stop gaps to even the playing field in the form of load timers, which makes the speed demons wait behind a timer.
You can't advance until you exceeded X amount of time, or the last person to load has load.
Lately there are not many open world games now even with map transitions.
They will take a bit longer to initially load, but after that you wont notice any difference from a mechanical vs a SSD.
However Rumor has it that Unreal 5 will require the speed of a SSD, which honestly makes no sense as a PC's RAM is faster then a SSD, hence it would make more sense to load whatever needs loading on RAM after buffering it off a SSD, and most Mid-Tier Gaming PC's now have at least 32GB of ram.
So does a SSD matter... its completely dependant on what game you play.
What do i use?
Well i am a speed demon, so i have 6TB's of nVME + 10TB of SATA SSD storage.
I do not run mechanical drives in my system, as i have a very short temper when it comes to waiting for anything.