I'm having trouble finding what I remember seeing maybe 4 years ago. It was an all in one cellular component with an esim. This is the closest I can find to what I remember seeing. It may lead you to some other solutions.

https://1nce.com/en-us/1nce-connect/10-dollars-for-10-years

I remember seeing stupidly cheap prices for cellular chips, and when I looked into it, it looked like they had bought up a bunch of bulk bandwidth on some really old tech, like 2G. The offering wasn't a lot of data per period but certainly enough to wake up and upload a small amount of data regularly. Seemed like an obvious product, I know that if I'm doing a design, I don't want to have to rely on ongoing costs. I'm surprised I can't find more hits like this one. It's possible that peak IoT led to some crazy business models that had no chance of sustaining. I think they may have banking on the network dying before having to figure out how to purchase more bandwidth.

Digikey was no help. Googling "Lifetime Data Cellular Communication plan" did lead to some other potential interesting hits. chatgpt almost gave me interesting things to look for, but it mostly pointed me at consumer good. Good luck.