First things first.
I have spectrum too.
They NEVER promised 200mbps. They say "Up To 200mbps".
How old is your router? Is it a cheap one?
If you havent upgraded your router in a few years at least, then I would try upgrading, especially if you have a ton of devices connected to it at once, as old routers use older technology that is worse when handling multiple devices at once. Additionally, older routers may not be able to reach the advertised speed of your package.
If it's a cheap router, OR an ISP provided router (meaning Spectrum gave you the router), then it probably isnt enough to handle all of your devices, which will result in slowdowns.
Have a newer router that is good?
Then check the channels your wi-fi is using. You can look up on how to do this on YouTube. Essentially, most routers will automatically connect to certain channels which are also used by everyone else around you (Neighbors and such), which can result in interference and slowdowns.