I'm not sure how far back you'd consider "modern" but back in 2000, Microsoft Office was unreliable, bloated crap that would occasionally refuse to open, reinstall or be repaired; I had to occasionally resort to reinstalling Windows entirely. Adobe Flash would randomly chew up the entire CPU after playing certain applets, even after the browser closed. Browsers? When they crashed, which they did often on some machines, they had no session restore. Boom.

Sage Payroll across a network - even a 100Mpbs/switched setup was laughably slow because it would IO bytes at a time.

Symantec's antivirus would refuse to update, even on freshly-installed servers. Norton had official instructions on troubleshooting LiveUpdate which included having to unplug the modem to fool it into thinking you were offline.

Windows would hang, crash, run like treacle, die if you plugged in a printer, insert a blank CD-R that hadn't been formatted properly.

When iTunes first came out? Oh god, one early version broke the Windows Installer somehow, killing all MSIExec-based software in the same way.

IME, software is just as bad as it always has been. Microsoft still ignore their own best practices, design guidelines and even user consent recommendations. Electron may be new but it's as efficient as software has always been: insultingly, laughably so. Installing printer drivers seems easier until you realise, three months later that it's pointing to an IP address, not a host name, when it's given a new one. Forced to set up an online account to scan, or even just login to your computer.

I don't even have to work on enterprise software which is why I do not have grey hairs :-)