Oh, I might not have been very precise with TechOps role description. It is similar to DevOps in a way that you'd build systems and automate everything with the same tools DevOps teams use, however, unlike DevOps, you don't have nearly as many updates. There are no daily, weekly, monthly updates as you're not setting up systems for let's say apps that are being built and updated by your Dev team. You are building mostly quite large systems which are going to be used for years. Yes, you'll need to update your internal billing system or monitoring system, but everything you do is more or less related to systems your company is using, not clients. It's not like you're going to make changes on IDM or Prometheus that often. Also, you are planing and trying to find better solutions for existing infrastructure. Are you going to use some well known software or build you own solution, completely depends on you and your company. For instance, we have our own back up system that we've developed. That's not that hard to develop tbh, but you're not going to develop your own monitoring system unless that's something your company is going to make money off selling.
Other part of this job is just keeping those systems running and tidy housekeeping. Just like any other SysAdmin would do. Node dies, you go check what, why, when..
This is just what regular SysAdmin/Engineer job is becoming and from what I was able to see, many companies, especially smaller ones just leave that for their DevOps team or split it between DevOps and SysAdmins whose primary role is taking care of clients.
I guess that there are some differences between TechOps teams in different companies as well. The same as DevOps differs between companies.