As a senior engineer today, I'm responsible not only for knowing
I thought the exact same thing when I started as a software engineer in 1996, almost 20 years ago. Only back then we actually generated HTML in C++ on the server (with home-brewed "html template" processors.) And we had to deal with things like COM, and browsers were far less standardized. We also had to deal with database design, only we had to make home-brewed Object-Relational Mappings, because the frameworks for that weren't that good either. Marshalling an object from the database through the business logic and onto the client and back required all kinds of hand-written code. We also had to worry about deployment, but we could only dream about something like WiX. I don't want to hear any complaining about build systems if you haven't been subjected to the horrors of makefiles. We had source control way back then too, but it was less flexible, less salable, and more difficult to use.
And check this out. If we didn't know a tool or API or algorithm or data-structure (oh yeah, we wrote our own back then), you couldn't just google the answer. You had to actually find it in a book, or learn it from a friend or colleague.