The practice is that
- you give your precious data to third parties
- that the safety problem now shifts from keeping your computer safe to keeping data in the hands of third parties safe (and this does not always play out in the way we would like, see codespaces for a recent example)
- that even the client side safety is a problem, the 'distribution advantages' have also been recognized widely by the blackhats.
- that we end up being tracked from here to Tokio and that the web is rapidly turning into a series of silos that try to have as little as possible to do with each other.
- that the final experience is almost always sub-par.
The theory is fantastic, but the practice leaves much to be desired.