1. When people are financially incentivized to run servers, they always will.
2. If a crypto protocol doesn't evolve at the pace of available innovation, that particular blockchain will be superseded by a new one. That said, a (truly democratic) evolutionary process is a core part of every blockchain specification.
3. You can get blockchain data via public (and federated/proxied) API, but you can always cryptographically verify its veracity, and your edge device (e.g. your smartphone) can do that. The same the other way around, you cryptographically sign the inputs you send to the networks, so that no federated API can tamper them, because the secret key stays on your device. This is referred to as the "trust-less model".
2. If a crypto protocol doesn't evolve at the pace of available innovation, that particular blockchain will be superseded by a new one. That said, a (truly democratic) evolutionary process is a core part of every blockchain specification.
3. You can get blockchain data via public (and federated/proxied) API, but you can always cryptographically verify its veracity, and your edge device (e.g. your smartphone) can do that. The same the other way around, you cryptographically sign the inputs you send to the networks, so that no federated API can tamper them, because the secret key stays on your device. This is referred to as the "trust-less model".