The cable was always slower due to its shared architecture. The fiber optic system in our area is spotty at best.
Long story short, DSL is broadband, but it may not be fast enough for your needs. I am with you on NN. It needs to stay.
If DSL is 3 Mbps/768 kbps or more, then it IS broadband, as per FCC definition, from before 2010.
DSL's architecture is shared, not cable - I had 28 kbps at homework time with AT&T before booting them. The plan was sold as 6Mbps.
Cable can throttle you, as the same line brings 10 Mbps, 100 Mbps or 1 Gbps right now, with the same high-speed modem. This how they provide different tiers of service, a step that actually takes more work for the provider, the slippery slope in technical support.
Fiber-optic from AT&T and Verizon are still customer service glitched services. Apparently, Google has better standards.
FCC to FTC good or bad!?