The how is pretty solid, SpaceX has a very strong track record. The uncertainty is mostly in the when.

It is unfortunate that Elon’s state of mind has become more questionable. But SpaceX is a whole lot more than Elon and they have achieved remarkable things. Just take the Elon presentations with a boat load of salt (mostly concerning the timing) and enjoy the spectacle that SpaceX delivers. It is just ridiculous what they are aiming for and so far they seem to be able to deliver … eventually.

They cut off the engines a couple of seconds before reaching orbital speed for safety. Until they prove they can control the ship on orbit they can’t risk having a 16 floor tall 125 ton steel tower coming down in a random location. This is unrelated to any of Elon’s shenanigans.

There is nobody who knows even the slightest bit about space flight that doubts Starship can reach orbit.

SpaceX has many things to get done to make Starship the fully reusable rocket they want it to be, but picking orbital speed is just about the weakest argument against it.