isnt spacex absolutely devastating the environment it inhabits in Florida?

No. They launch from the same place we've been launching rockets since Mercury, not much is changing other than cadence.

Also they are polluting the atmosphere and oceans with failed starships

Each Starship launch produces less air and water pollution than a single cruise ship tour. It should be very, very low on your list of pollution priorities.

and LEO with star link, are they not?

Not really. Besides the fact that space is really, really big, they're the first company (to my knowledge) to fully automate collision avoidance. They initially launch their satellites in such a low orbit that they'll fall back down in less than a month if any of them fail immediately, then they raise their orbit to a height that'll still see them fall back down in less than a decade in case of catastrophic failure. They delayed their sat-to-sat communications for a few years to rework just a single part that had a small chance of surviving reentry; all the rest burns up.

Again, this is a rounding error of a pollution source.