I've been reminiscing a lot about calculators lately. I started learning math just when electronic scientific calculators were replacing slide rules as tools for engineers.
But scientific calculators are themselves almost extinct outside of the classroom, because computers, smartphones and tablets running powerful CAS or numerical software can do all the kinds of computing you really need... unless you're not allowed to use them because of classroom or exam restrictions.
So the market has contracted to education, and the high-end calculators sold today, though they're extremely powerful, are very much catering to students rather than to engineers or scientists. There's a lot of power siloed into user-friendly apps, but less ability to link those together into powerful custom-built systems of your own design.
And inevitably, because I'm getting old, I have a lot of nostalgia for old ones... particularly for HP's RPL line, starting in the late 1980s with the 28C (which was woefully underpowered, but the potential was there) and continuing through the very capable 28S and 48/49/50 series.
The ones I actually had were the 28S and the 48SX--the latter got stolen after just a few years; it was too damned expensive to leave lying around. I still have the 28S somewhere though the batteries for it can be hard to find. But I've been getting back into messing with them through emulation. Here's Calculator Culture's review of the 48SX that goes through its innovations, strengths and weaknesses.
https://www.youtube.com/watch?v=yujtxo5efbE