Just checked into this and my current plan is apparently at 40mbps, but my speed tests were apparently slightly above that, not sure how that works. Looks like I can upgrade to 80mbps for only $10 more a month, that's a no-brainer. Unfortunately, modem-wise, it looks like they only have one upgraded option, and as far as I can tell I have to use theirs (either $15 a month lease or $200 one-time purchase).
My plan is for 40, but I'm somehow clocking in slightly above that. My ping is 19ms according to the CenturyLink test.
I'm not sure whether you would need to upgrade your modem if you upgrade your plan to 80 mbps. Your current modem might be suitable for that higher speed as well. You would need to post the modem specifications to check that.
I actually don't have much of an issue with it really. I trimmed down my layout from 7 monitors (in my office) to just three (laptop + two externals). Most of what I do is pretty simplistic, so I don't need the best of the best, however I will certainly be upgrading to the 80mbps here shortly since it's only an extra $10/month. I don't play games or anything like that, so for me it's only needed for signal and basic web browsing.
I'm only running 30 Mbps (fiber, symmetrical 30 Mbps). Have been since 2016. Never found a reason to throw away more money without benefit. It's plenty fast enough for everything I do.
Ethernet is technically superior in terms of performance, but this might not be a bad alternative to running cables all over the interior of the house. Have never tried it.