No OS updates, unless promised at release. Some security updates, though. They’re GPL violators, and don’t release kernel sources, which makes 3rd party OS images harder.
Devices are generally easily repairable,they sell spares, and their support also sends you parts during warranty period if you ask - I just received a new battery for my titan slim.
Paid and FOSS are not mutually exclusive. You can always build packages yourself if you don’t want to pay. A well executed implementation might allow some projects to drop or reduce their play store efforts.