[bachmeier]

Likely a different field, but

> 1. They had competent PhD advisors

I'd say fit is very important. Some advisors will provide students with feedback, give them direction, and wait for the students to come back with output. Other advisors will micromanage students, give them tight deadlines, get upset if they don't strictly follow everything they say and every deadline, and generally give the student no freedom to do anything on their own.

The thing to keep in mind is that grad students usually work well in one of those environments, but few students will thrive in both.

> as a married student I had to balance my research and teaching responsibilities with the needs of my spouse. It added a level of mental and emotional stress my single colleagues didn’t have to deal with.

This can go in several directions. Your experience is obviously the most common. In some cases the spouse is counting on the grad student to finish and get a high-paying job. They take care of everything like paying bills, shopping, cooking, etc. I've also seen cases where the spouse sacrificed so the grad student could finish (so they could have a higher income and start a family) and it put so much pressure on the grad student that they were breaking down.