Any firm worth working for will have this as either a stipend, or otherwise handled as part of hiring remote workers. Any one that doesn't make it easy and cheap to be comfortable and productive remotely will miss out on talent because of that.
This is just not true. I have never worked for a colocated company that pays for you to set up your home office. Most do not hire remote works either so there is no predefined (and budgeted) setup
We'll also see if in the face of double-digit unemployment (don't think that's going to resolve itself the minute we get back to work) companies that don't have these discretionary benefits loose out on talent...
It's entirely possible to lose out on remote talent by skimping on the remote experience, while still "successfully" filling the position.
Is it really impossible to invest in the tools of your trade?