Heh, ironically, the "wired" internet is surely 10X or more faster than a decade ago. Anecdotally, I have a 1 Gbps connection now; year or two ago I had a 250 Mbps connection, and 2-3 years prior to that it was 50Mbps. Ten years ago it was, what, 5Mbps or 2Mbps.
But the price of cellular data has come way down. For instance when the iPad was first introduced, it was only available in the US on AT&T and was $25 for 2Gb of data per month. Now I'm paying an extra $20 a month on T-mobile for unlimited data for my iPad.
The cellular iPad wasn't even worth it for me until I could get unlimited data for $20. For that amount the extra convenience of not having to tether and basically having a second phone is worth it since you can get and receive regular phone calls to your paired cell number from an iPad even if your phone is dead.
I pay a total of $180 a month for 5 phone lines unlimited data on each + an iPad, unlimited 512Kbps tethering on each + 10Gb of high speed tethering on one for my son who uses his cell phone for his only internet. This is with T-mobile. They also throw in a family Netflix plan (4 simultaneous streams) with it.
As to bandwidth caps: for $100 including fees, you get unlimited on Verizon, which has a 22 GB soft cap per line (in practice, you can use way beyond that).
Your point about duopoly is completely divorced from facts. The cell carriers are in a market with four competitors, and invest massively in infrastructure (tens of billions of dollars a year). Cellular has improve way faster than many other areas of technology over the last decade. 10 years ago, I had a Core 2 polycarbonate Macbook and AT&T 3G service. The former is still a perfectly serviceable computer (the new Macbook is maybe twice as fast). But my Verizon LTE is probably 10-20 times faster than my 3G service.
What else do you use that is 10 times better than it was a decade ago? Google Search? Gmail? Facebook? iOS?