Neither of your examples make sense. To do anything on cellular bands requires a license. Consumer equipment is locked down to get type licenses. Carriers need

Neither of your examples make sense. To do anything on cellular bands requires a license. Consumer equipment is locked down to get type licenses. Carriers need their own separate licenses from the FCC or local equivalent. You can build your own basebands but you can't do anything without a license. No carrier, paying for licenses and operating the network, is going to freely connect you to their infrastructure. People have collectively decided cellular networks is more valuable/useful to modern society than being able to goof around with scratch built cellular radios. There's other bands open to experimentation (ISM). Complaining about Google and Meta is likewise confusing. Meta and Google can censor whatever they like. They don't owe you a bullhorn. But they do not control the whole Internet. If you can get packets routing to you, you can still publish whatever content you want. You can build your own application layer completely ignoring Google and Meta. There's dozens of overlay networks built on top of base Internet routing that work just fine.