I'm also nostalgic for the early days of personal computing, back then there was more experimentation and when there was a greater sense of wonder about the possibilities. While I feel there are still a lot of exciting advances in other areas of computing such as artificial intelligence, I feel that innovation in the realm of personal computing has stagnated. Moreover, since the rise of Web 2.0 and smartphones, personal computing has been the target of aggressive monetization schemes and UI/UX trends that, in my opinion, have degraded the computing experience compared to the pre-Web 2.0/smartphone era. Of course, I don't want to look at the past with rose-colored glasses; while I'm nostalgic for Windows 95/98/NT/2000, I also feel Microsoft's monopolistic actions in the 1980s and 1990s and the crushing of competitors played a major role in shaping today's situation.

If I were a billionaire, I'd start an R&D group that is dedicated to improving the personal computing experience, producing an open source system.