Probably because the individual engineers working on Takeout care about doing a good job, even though the higher-ups would prefer something half-assed. I work for a major tech company and I’ve been in that same situation before, e.g. when I was working on GDPR compliance. I read the GDPR and tried hard to comply with the spirit of the law, but it was abundantly clear everyone above me hadn’t read it and only cared about doing the bare minimum.

There’s no financial incentive for them to make is easy to leave Google. Takeout only exists to comply with regulations (e.g. digital markets act), and as usual, they’re doing the bare minimum to not get sued.