I discovered early on that Internet speed and things like ping & stutter are unrelated. Paying for a more expensive speed plan didn't really change my online game play experience.
I had a regular no-frills plan (forgot the speed) but after I got into online gaming and had some problems, I upgraded to the highest speed plan offered. Much to my disappointment nothing changed. The only differences were shorter download times when I would buy a game from Steam or download some new update. Game play remained unchanged. My ping was still too high, resulting in delayed responses.
Outside of gaming, you might need higher speed for streaming 4k or 8k, as it takes more data to feed your 4K TV while streaming from Netflix or whoever. Btw, Netflix will tell you themselves that you only need a minimum of 5Mbps for regular HD, as long as that's the only thing online. If your kids are gaming in another room you might have some hiccups in streaming.
I've been streaming from various sources using their free trials. For the same internet speed, most streaming was just fine while others sources had problems. It would mess them up when I wanted to rewind back a bit during a movie, sometimes making me start the movie from the beginning. So that's another variation to factor in.