"End of life"? Do you mean "End of SUPPORT life"?
The Obi110 will keep working until it breaks. The Google Voice has always been a bit iffy because you have two companies involved, one who enjoys have OBis connecter (or at least tollerates them), but will stop that if itey decide to.
Obi decided to stop putting effort into the 100 so they could build better products.
My old computer company made a propitiatory maiframe and kept rewriting the operating system to allow programs compiled decades earlier to still run. Even Microsoft never did that. My company found value in letting people who spent monet on hardware decades earlier (maybe $250,000) to keep using that software even after the company who wrote the software may have gone out of business long ago.
I cannot see a company spending 'boatloads' of time and effort on a device which was so reasonably priced. I guess if haven't recovered the cost many times over, then perhaps you should be concerned.
As an aside, I once bought a riding mower for $800. It lasted a year and a half because I was moving 8 acres with lots of rocks. I saved about $2,000 by not having a guy come in on a tractor and do the work. I felt I was ahead and let that poor mower go to its final reward.