First: You shouldn't care about what others think.
I can understand why your husband thinks it's too late for him. I am also in my 50's and my daughter has a 6 months old son and I could never do that again. It's not just now but if that newborn is 20 your husband is 71.
I have been using computers since the early 1980's, using Linux and Windows for over 30 years now.
Money is not the issue. Microsoft and Google are among the largest contributors in the OS community, most meaningfull packages have been bought, adopted by larger companies.
The problem is the Linux community itself. How many distributions are there? Every piece of Linux software has to run on all these ditro's, that is impossible without compromises.
For corporate use OS is hardly usable, most companies want support contracts on everything they use and that is not possible.
Ok, the only country in Europe currently still using dial up is Croatia, the rest of Europe has shutdown those services years ago.
Telephone wires have been used for aDSL since the early 2000s and stil used for vDSL but dial up?
It's funny that the US still has dial-up. In the Netherlands the last dial-up provider stopped their service on oktober 1st 2021, and that was already late.
First: You shouldn't care about what others think.
I can understand why your husband thinks it's too late for him. I am also in my 50's and my daughter has a 6 months old son and I could never do that again. It's not just now but if that newborn is 20 your husband is 71.