"Impossible"? Likely never. The real question is if/when hobby developers will ever lose interest in doing so.
As more & more businesses & websites completely block devices using Win7 or an older browser version then it will become obvious that continuing to try to use Win7 &/or the older browser has come to an end. May be different for everyone. Some are still using XP & even older M$ versions on older machines but not to access the internet. Rule is: we go till we can't. End is a bit different for everyone depending on their individual computing needs. Me? Mine is a survival tool. I use it on 2 platforms for investing. I use it for VA healthcare communications. For all other government business like tax filing & SSA. 90% of my food needs are ordered/delivered via this laptop. All my bills are paid via this laptop. I have ZorinOS & a modern private browser ready to go the very minute my access is compromised. I think modern access security requirements will be what drives me away from Win7/FF. Live photos, finger prints, eye scans & 2FA keys are becoming more accepted & common. HD+ cameras & devices better supported with more modern software. You just have to let your own individual needs & requirements dictate "when" it is time to cut the cord. My 73rd birthday today. Making the rounds, checking for news or updates & keeping my account alive. Watching a couple other forums here as well. Still chugging along with my Win7 laptop, my MSE continues to be updated & works fine. FF 115 updated still working on sites with the help of my VPN in some cases. My secondary ZorinOS is primed & ready to go. Weather is fair, oceans are calm & smooth sailing ahead for now. Pray the same for all who are left here.
Happy birthday , my 72nd is almost here as well (in September). Like I mentioned before, I haven't had any problems with r3dfox 152.0.4 and the User-Agent switcher and Manager add-on for Firefox visiting any sites including my credit union. The only limitation is that it won't play DRM content making watching Amazon, Disney+ etc. much harder as the workarounds have quite a few limitations.
I think we still have options that work for as long as the internet sites continue to communicate with us on our Win7 rigs. Lot of new security protocols being designed & incorporated; some mandatory for certain access; that we will eventually need to accept & evolve for. For now, I access everything I need to; everything I want to; in a fashion I am satisfied with. At our age we begin to wonder if we might just be able to outlast a very volatile world. Happy 72nd to you next month & many more.
so just tested r3dfox v140.14.0 on another Windows 7 machine and just recognized that it is highly modded with a tons of extra options.... also with its own icon etc... I understand the intention of the developer here, its fine. But personally i just want a working FF 140, (or the next esr release) which is just ported to Win 7, so very close to the original which runs on WIn 10/11. So is there some alternative, except FF 115? Just a "clean" Firefox Port for Win 7? or are all these ported browsers modded in some way?