Mostly because they use TN LCD technology which is indeed old. IPS is mostly used in active matrix displays - TFT's, with high pixel density, not passive displays with a few segments.
The exception to this ia VA - vertically aligned - displays, which is a similar kind of technology that allows much better viewing angles. I say exception because, I think only one company makes these and they are used on old character displays that use 0.5mm pixel grids (which is massive compard to modern TFTs/OLEDs). So it's kind of an odd mix of old and new.
Interstingly, VA dispalys seem to be even better than IPS, but for viewing angle and contrast, its the only technology I've seen applied to non-TFT passive dispalys. You may be able to find a seven segment VA display somewhere. The few 16x2 character VA displays I have have stupid viewing angles - at least 170 in both axis'.
I just googled VA clock display and the first result...
https://www.amazon.co.uk/Braun-Fast-Charging-Automatic-Backlight-Adjustment/dp/B09T3GWQV9surprised you didn't google it first