It's probably very hardware dependent now, just like it was back then. My calculator opens to interactive in much less than 1 second, but I've got a 9800x3d and fast memory and nvme drive. The other guy saying his start menu takes 8 seconds to open probably has a pretty shit computer.

I definitely got the stupid hourglass in win 95 when trying to open anything, but my understanding of computers at the time was that black ones were faster than beige ones, so my computer was probably shit.

I tried to look up calculator win 95 vids on YouTube, there are a couple. One gets an hourglass - but less than a second, one is instant, one shows the calculator crashing lol.

During this I also found out that Microsoft Calculator is open source: https://github.com/microsoft/calculator