Before I was on the 75 plan with old equipment and most of the time was in the 30s and I supported 2 firesticks, 2 computers, 2 IPads, DVR for security, a weather station, plus a few other minior things. Rarely had any issues but sometimes it would be slow and the firestick may pause for a second or two. New modem and router plus Comcast upped my speed to 100 and now no issues plus I added 3 WYZE cameras.
I would think if your actual speed was 25 or more you would be okay. You do not always get the plans rated speed even with top of the line equipment. Your modem and router also need to be factored in. Plus with the firesticks, WIFI channel (2.4 vs 5) and distance makes a difference. Higher makes for a better experence.