Earlier quoted context omitted.
I'd guess that migrating from any of the local cloud DB variations (Aurora say) is unduly hard once you've migrated to it. But that's just a guess. It is certainly a PITA to migrate, I know that for sure.
I agree with that, but given that a lot of the DBs on AWS and Azure are proprietary software (eg Cosmos and DDB) I'm not sure what ofcom proposes doing about that.
They merely say that after doing a market study, they noticed that: egress fees are significant, technical barriers to interoperability are in place and the discount structure based on committed spending is suspicious. From their point of view, that warrants an actual full investigation by the Competition and Markets Authority.