I'm pretty confident that the vast majority of union workers are expected to work from their employer's business premises. Workers should unionize if they're being mistreated, but it's not a magic wand that means I can get whatever working conditions I'd like.
US government agencies still have some of the lowest RTO rates in the country (compared to other employers) precisely because of federal employee unions.
I don't understand why this has been so downvoted – although it might be true for now, there's a deeper truth that it's true that any union benefit has to be fought for and constantly defended between negotiations. (Which is why unions usually have legislative and political advocacy arms to codify these benefits – so they don't have to waste barganing power on them.)