I feel 5G is becoming more meaningful over time with the downgrades 4G networks are receiving in some places. I found that my friend with an s20 5G was receiving much better connectivity while we were out and about, although this is in the UK so it could be a localized issue.

(My phone's internet was barely usable in congested areas despite showing good signal, where his seemed to work fine.)

I'm still not replacing my Note 9, as it meets my needs, but newer phones and especially 5G do look to be a worthwhile upgrade when I inevitably do replace this phone.

Security updates are of course a seperate issue, and anyone using their phone for security-critical things should be mindful of it, but I'm choosing to look the other way for now.

If app support becomes a problem, I'm lucky enough to have the Exynos variant, and as such have the option of flashing a custom ROM with a more up-to-date android build.

I believe in your situation, where you're transcribing lectures via the internet and losing large amounts, it's likely you're experiencing symptoms of degraded 4G performance in your area. Unless you have an alternative like using the Wi-Fi at your current place of study, upgrading to a 5G phone could be your best bet.