IME you have to limit their game time if you want them to spend time doing other things. Not all children will self regulate the amount of time on it. A lot of them find it so compelling that given a choice they will do nothing else. DS1 did and at this age he would literally do nothing else, even if we limited the time he would spend the whole of the rest of the time complaining it was not screen time yet, flopping on the sofa, sighing like a lovelorn teenager, winding everyone up for attention, insisting we do things with him, asking how long it was until it was screen time or asking for jobs he could do to earn screen time. We had to cut it RIGHT down before this behaviour went away but he was older by the time we worked that out!
Do you have the Switch parental control app? You can set it to automatically turn off at a set time and/or set a total time limit per day, different at weekends if you like. I currently just have it set to play an alarm because I think it's important to get their buy in but if we were having trouble sticking to it or I wasn't actively supervising, I'd probably enable the option for it to fully suspend the game. It comes up with warnings at 15/10/5/2/1 minute before it turns off so they have time to find a good place to stop - some games don't save progress if you stop in the middle of something.
DS2 is not quite 7 yet and struggles with reading but goes on his bike/scooter, will still do all manner of "science experiments" in the garden (water/sand/mud play with whatever added) plays with his younger brother, plays with stuff like a cheap Ring Toss set we got in the €1 shop, builds Lego (we are getting quite into the more advanced Technik stuff recently as he likes the idea of building machines) and will draw some quite elaborate things especially plans or maps. I used to be really into computer games when I was younger, but because it was the olden days 
I did not have my own device or unlimited access to it, so I did used to spend quite a lot of free time drawing plans for Sims houses etc on squared paper - I have tried to encourage him to draw out plans for Minecraft builds, machines etc on paper but it doesn't quite appeal to him or perhaps not yet. We have Marble Rush and Gravitrax because DH is interested in these - he plays more with the Marble Rush but the Gravitrax is better for 7/8 I think. And yes we have a few Hot Wheels sets and he will still build Brio tracks as well, although more happily if someone builds with him. Oh and we have a couple of those logic type games, too, which are almost like mobile puzzle games but in 3D plastic - we have one where a rabbit has to jump over toadstools and foxes, and the one where you have to slide the cars out of the car park in the right order.
I find that in order to get him doing stuff independently, it helps if I show interest and/or do it with him a few times initially or set it up and sit with him with a cup of tea or something, or doing my own version, and then after we've done it together a few times he gets into the groove of it and will then be coming up with ideas to try out on his own or with his brother or a friend. But I can't push that too fast. If he senses that I'm trying to push it off on him doing it alone he will reject it. I try to pick stuff that I actually find interesting/fun myself and then I alternate saying yes OK let's play something together / no I need to do X right now or have a break/sit down/drink etc.