We have had a Roku Streaming Stick, Roku Ultra, Apple TV, Fire Stick, and a ChromeCast.
First off All did exactly what they said they would. They provide TV over the internet.
Roku, that is the one we use the most. We currently use the stick on the guest room, and the Ultra on a 65 inch Sony in the main TV room. None of our TV's are 4k and we don't have a internet provider that would support 4k. I use Inteset remotes with the Roku Ultra. It is about $27 bucks and works with IR. I use this because I have the main TV connected to a home theatre sound system. One thing, the Ultra Remote seemed to go through batteries faster than prior models.
Apple TV. I use the interset remote here also. Different reason, however, the Apple remote is horrible! The include a touch pad remote on one end. It is very sensitive and multiple times at night I tried to use the wrong end to control the Apple Tv. Picture contrast on Apple appeared a little better on the Apple than the Roku. I did find a way to tweek the Roku so now they are about the same. I will replace the Apple Tv with a Roku, most likely the Streaming Stick Plus.
Chromecast. I don't use this anymore. It worked well, but there is not controller for this device. You control it using you phone or tablet. That works well, I just don't like using my phone to control the device. I will say for $25, (I think black friday pricing a Best Buy), It is a great deal.
Fire TV. I gave this one away. Works great with Amazon Prime and other Amazon products. It seems to push their products. And, this brings me to the reason I got rid of it. Amazon and Goggle do not play well with each other. I use Youtube TV as my prime tv source. It is not available on the Fire TV. You can side load it, but, for me, it is not worth the effort and many people say it is buggy.
I also have two "Kodi Boxes". Both will support TV apps, however, I feel these are more cumbersome to operate. More of a hobby device.
Why so many? Well, cable was costing me north of $120 a month and they were going to raise the price. Youtube TV cost me $40 a month. I have had a Roku for years. I got the Apple TV with a three month prepay on Direct TV Now. I got a Chromecast to try. It was cheap. I have tried Hulu Live, Youtube TV, Direct Tv Now, and Playstation TV. All of these, except Direct TV Now, were free trials. When we setteled on Youtube TV, we also settled on Roku. It is the easiest for DW to operate. The two Kodi boxes were toys. I believe the Nvidia might also be a good compromise, but at $150 a box, I don't think it fits my profile.