I explained the Twitter mission here:-
Elon & Twitter
The benefits of working there or not working there here:-
Elon & Twitter
@ZenRockGarden beat me to it as to why those two points specifically are not at all comparable to Tesla and SpaceX's mission statements.
I will add further unlike with Tesla and SpaceX, Elon does not have a clearly laid out plan to achieve either of those goals. He did for Tesla, first release a higher end car and then go down market to achieve volume. For SpaceX it was reusable rockets to reduce the cost of space travel and using the funds from that to eventually establish a colony in Mars.
For Twitter, for the town square idea, Elon already walked back on opening up on Twitter due to advertiser pressure, so it is pretty clear Twitter will remain moderated and under the pressures of advertisers. The only additional revenue source he laid out was the $8 checkmarks, and he walked that back also. There have been no other viable ideas for additional revenue sources to free Twitter from control by advertisers.
For the financial idea, he has laid out no plans to achieve it. It is clear he was inspired by Wechat, but he have not given a path way to achieve that.
The other huge issue is Elon didn't go in with a clear determination. He did everything possible to try to get out of the deal. He even bad mouthed the company. There was no determination like when he started SpaceX and funded Tesla. Employees are not blind to this given this was very public and widely reported (even people that don't follow Twitter or tech news knew about it because it was all over mainstream media).
When I was younger I would have been strongly attracted to working at Twitter, and would have paid an airfare to the US just to attend the job interview.
That has nothing to do with politics, I'm firmly left of centre.
Being the category of person who would loved to work for Elon, doesn't stop me seeing why others don't want to work for him.
These days I am too far past my prime to attempt to work for Elon.
Plenty of people were attracted to working at Twitter back before Elon's current conditions because the benefits were great, there was remote work available, and it was possible to maintain a good work/life balance. Now it's a different story. Elon clearly wants a workforce that will work for long hours in a highly motivated fashion, just like the early days of Tesla and SpaceX. But my point was that was driven by a very strong mission, just don't see a strong mission for Twitter. I'm not saying there are no people willing to work there even under those conditions (there are certainly Elon fans out there that might), but saying it's not at all same as with Tesla and SpaceX.