After 3 (now) years of having the switch, nothing has happened to it, the joy-cons work perfectly fine, there is a small issue with the right one but it's not significant and you don't notice it when playing. It doesn't freeze at all, it doesn't heat up easily, and let's say that I have played for over 1500 hours and a little more on the switch, and it's like new. I don't understand why some people leave critical comments like: "I bought the switch and it's not worth it because it has so many Nintendo games and I don't like them, I want to play Fortnite, FIFA, etc." If you wanted to play those games, you should have bought a PS or Xbox, I'm not saying you can't play them here, but not with the same FPS and graphics quality, etc. Also, some people complain about paying to play online in certain games like Mario Kart, while it was free on the 3DS and Wii U. Yes, I agree, but the servers were worse. You might ask how I know, well, I had a 3DS XL, so before buying, you should know what you want. So far, I have completed Zelda (I'm playing it for the third time now) and Odyssey (update: I finished Metroid), I still play many other games like Mario Kart, Mario Strikers, Pokemon Violet, Super Mario U Deluxe, and more. I also wanted to mention something for those who will buy it now: It heats up and makes noise in the first few days, as I have understood from friends and myself. If you're going to play online, it's better to get the expansion pack. Your first game should be Zelda: Breath of the Wild, don't make the mistake of getting it with black joy-cons like me, and finally, get the 2019 version because of the better battery life. (Oh, and also consider an extra cost for a micro SD, preferably 128GB).
Now I will talk about the technical aspects because many people are interested in them: 1. Graphics and resolution: Most Nintendo games will run at 60fps, while third-party games will run at 30fps, with some exceptions. If you have it in handheld mode, it will output at 720p, while on the TV it will output at 1080p with better graphics. 2. To connect it to the TV, you need the dock (a base) that takes up very little space. Finally, battery life: Depending on the game you're playing, for example, if you're playing Zelda, it will last 2-3 hours, while in a less demanding game, it will last 5-6 hours.
Lastly, I want to say that you should get the switch not because you can take it everywhere or because it's the best handheld at a regular price and not 1000€, but for its exclusives and the magic that its games offer. That's all from me. I hope you have a beautiful day!