But the trend of soft power buttons in test equipment is annoying.
There is little to no good reason why such gear would need to have a soft power button. They don't have remote controls to turn them on and they are not working on so much data that the OS could corrupt itself by forced power downs. RAM is cheap now days so simply run your OS from a ramdisk image while keeping only large static files in flash along with a settings file that gets written to in a safe way. Test equipment spends most of its life in the off state. You don't even use your scope for 10 hours a day on average even if you really use your scope a lot. Let alone use some more specialized bit of gear that you perhaps only power on a few times per year.
What makes things worse is that all of this gear uses switching supplies now. Okay they do waste less power than a oldschool transformer at low loads (When properly designed) so that lends them well to soft power off. But these things are also a lot more fragile. Mains power can have all sorts of surges happen and is common to get stuck by lightning. These surges can blow the primary side transistors in switching supplies pretty easily, but a big chunk of copper and iron doesn't really care as long as its less than the few kV of its insulation resistance. If you try pushing too much voltage into a transformer it simply saturates and draws a huge current while the output just rises a bit above normal. Of course it won't save you from a direct hit but i seen a lot of switching supplies blow up from lightning strikes while all transformered things in the same building kept working fine.
The only exception is instruments that have ovenised things in them. Often old gear had a small standby supply that is wired before the power switch to provide just a few watts of power to an ovenised crystal or something so that it drifts as little as possible. So i suppose if you have that then a soft power button is easy to do and saves you having an extra PSU.
There's a few things you overlook.
Some test gear has a hidden OS (often Windoze or Linux) that must be shutdown correctly so a soft OFF button lends itself well to these needs and fits well with SMPS supplies.
Much equipment is also more portable than those of yesteryear and again SMPS is preferable to save weight and cost rather than brute iron and copper.
Also, we've all seen enough years of SMPS to know their primary failure case is when hard switched rather than left powered for long periods.
And lastly, SMPS lends itself to international markets better than linear PSU's for multi-voltage and multi-frequency needs. At one time marine and aviation test equipment was somewhat specialized whereas today most equipment can handle these rather obscure mains supplies with ease.
Unlike the minuscule walwarts we all have for the likes of our phones etc, equipment with larger form factors do have the room to incorporate proper mains filtering that consists of adequately sized components, spark gaps, air gaps and common mode mains filters that make the modern SMPS quite robust. I've never replaced any in equipment I've supplied and can only vaguely remember one Siglent SMPS failing mentioned somewhere on this forum.
Luck I guess, but it seems not all other brands have shared this luck.