Absolutely. The fact that they choose to not provide this guarantee is a major red flag and a strong reason for me to not spend money on that platform. On the other hand, I have zero concern that my digital licenses of XBox or PlayStation games will vanish within the next couple decades.
Well, you should have a little concern. On my switch, I can buy games either digitally or physically for just about the same price. I buy most games physically, as one cannot guarantee the server that downloads games will work in 10 years (my Wii doesn't do this type of stuff now, but its less integral).
Pretty much any online game will be shut down, its just a case of when.
> as one cannot guarantee the server that downloads games will work in 10 years
While true, the pain point with Stadia is you have no downloads, for better and for worse. If Nintendo take their download servers down, you can still play all of your downloaded purchases.
On that note, I have much more faith in Nintendo's future handling of digital purchases this time around. They've put a lot more effort into the Switch's digital services compared to the Wii, which at times felt like an afterthought with the whole "WiiWare" artificial gatekeeping fiasco.
Keep in mind that this is a conscious decision. Google could easily provide a contractual guarantee to Stadia customers.