So employers don’t value long tenured devs? Isn’t there opportunity cost in those months

It's a gradient. I saw this play out recently where a top engineer dictated he needed to work remote three weeks a month. Management was OK with it but were clearly disappointed because he is an incredible primary contributor, manager, and is part of the cultural bedrock of the department. Their argument to him was that his career development would be stunted, to which he replied "no, I don't think it will be." and left it at that. He's now working his remote schedule, so we'll see what happens. I guess the point I'm trying to make is maybe 5% of the company could pull this off. Nearly everyone else management would be far less inclined to accommodate.

So be part of the 5% if you want that. Problem solved.

I know you're being glib, and I enjoy it, but there is some truth to this. Maybe a better way to phrase it would be, try to find a career where you are part of the top 5%?

There is. But the problem is that all employers are bad so none of them will lag behind when they loose good people.

The truly good employers are a rarity.

> So employers don’t value long tenured devs?

They don't, especially those who know they can find someone who's eager to jump in and work for less pay.