

Sure, it takes a bit of effort. But if you replace your routers with ones that have open-source firmware or actual workstations acting as gateway routers and running business-class open-source software, you can create a personal VPN between everyone involved that shows only one exit point to world+dog.
The trick is with ensuring that all YouTube stuff gets properly and comprehensively funnelled through this exit node - VPNs can easily leak data if not configured properly, and sometimes do so despite good configs - and implementing this even on other devices that require individual VPN connectivity (roaming, like phones).
Plus, having a mobile device’s VPN auto-recognize when it’s connected to a known good network, and have it automatically disable itself in favour of the VPN on that network, is not something that’s easy to do.
Finally, doing so without a high-quality, high-speed ISP plan can easily lead to an unusably slow VPN. The “mothership” exit node, in particular, would have to be gigabit or better - and symmetrical as well, so fibre and not cable - because it has both the node and connections to other homes and devices. If everyone started suckling the YouTube teat at the same time, things would likely slow down pretty fast on anything significantly less than a symmetrical gigabit connection.
Aside from the Rotary Un-Phone, there are pretty much no dumb phones anymore. Those that market themselves as dumb are just reskinned full-fat platforms.
Even almost all flip phones are smart phones with a dumb skin, as they run either Android or KaiOS.
The main reason why I would switch is for device security - a true dumb phone OS that operates purely out of the ROM and has no ability to install anything that could survive a reboot.
And for something that primitive, it would be a flip phone on par with the Motorola StarTac. Simple black-on-green screen, low-res display, with a calendar and address book as the only non-phone, non-SMS functionality.