I can't speak about all ISPs as I don't know their offer, but I can speak for Free that I use and is very popular. After all, they came up with the first box and were also the first to include WiFi.
you have no control over that hotspot
Wrong, with Free you can decide to turn the hotspot off completely, turn in on but keep in private (for your own personal use only), or turn it on and also share it.
If the hotspot is off or private, you can't use other Free APs for your own use. If you share, you have free access to any Free hotspot. Up to you to decide.
the company uses your payed line to make more money
As explained above, it goes both way. I have an extra service too for free, which is why my WiFi is shared. And other users are always handled at a lower priority, so it's really transparent to me: they just get the unused capacity on my line.
The wifi access is not directly monetized, in that no-one pay for it. But it certainly make Free more attractive as an operator: their boxes are very popular, so you can get wifi coverage mostly everywhere in a city as long as you participate in the sharing.
you have no control to your router whatsoever
You have control over some basic configuration like the DHCP configuration, basic port forwarding and IPv6 enabling for example. But it's true that the router belongs to Free and you don't have direct access like you could have on an OpenWRT box. If you want this you can put your own router behind, it's a bit wastefull but I did it at one point to have more control over DNS for example.
you have to login to the company's website and see what limited options they provide you
Yes, all the configuration is done through Free web interface and pushed to the box from their network.
in France I had terrible problems with latencies and ofc with Youtube
There was quite a big fight between Free and Google a few months back. Same kind of conflict as between ISPs and big network users like Google, Netflix all over with ISPs trying to get money from them. It seems it's been resolved recently for Youtube, it was really awful at the worst of the clash but is now ok (I'm not a big user though). Still, I'm waiting to see how it'll go with Netflix now they're present in France and if that kind of problem will happen again. I'm not super optimistic, but I've heard there are discussions happening. As I understand it the ISPs would prefer to be able to offer Netflix on their boxes with a cut of the profit in exchange of good network quality, and the big discussion is on the percent of profit for this... We'll see.