Solar charger for mine as well, but I charge a power bank/torch, I'd rather charge two units than one for the same wattage.
I think you're located in the States? That might have an influence on the effectiveness or otherwise of a solar charger. My own experience with one is that it is not reliable, especially on a bike. And that was in Spain, in summer. However, mine is quite old now so is not as efficient as the newer ones. It does work very well though, stationary in direct sunlight.
I've spoken to a couple of people who were trying to do what the OP wants to do.
Neither had managed to pull it off successfully, although I can't recall the ins and outs.
This article suggests a high power Son dynamo will just about keep a smart phone going, unless the rider can pedal faster than Froomey.
Reliable USB charging also appears difficult, requiring capacitors or some other in line device.
Cost is another factor.
A Son dynamo laced to a decent touring wheel is £300 or more, plus the electronic trickery to help with the charging.
I doubt the OP will want to spend that on his 'crappy' bike.
https://www.cyclingabout.com/best-dynamo-usb-chargers-bicycle-touring-bikepacking/
I have a Son 28* and a Cycle2Charge unit that makes me self-sufficient charging:
Wahoo Elemnt
Android Phone (minimum use)
Android Tablet (Minimum use)
Ipod (barely used)
Kindle (Used daily)
Recharge batteries for lights/headlamp
As well as powering my front lights (not simultaneously).
I travel pretty heavy and do not move fast, but an average daily speed of 13 kph will replace my daily energy use. (26 inch wheels)
*Previously I had a shimano hub dynamo and that worked as well. I have no idea if it was as efficient as the Son, but it worked.
For longer trips I still carry a 3 panel solar charger, but that has been ineffective on the bike. I use it for mornings/evenings or more likely long, lazy lunches. It effectively replaces the generation lost when I'm not riding.
The cheapest Son wheel from SJS is about 220, Shimano even cheaper. Pair that with a charging unit like mine and 300 will see you set up. In fairness, while it may be a crap bike the wheel and charging unit can be transferred to a new bike!
It is a viable option, in my experience. Especially given the fact that there are always opportunities to plug into a wall every now and then - unless you're really going off the grid. But of course, it really depends on your energy usage.
What a setup like mine does is give me the freedom to stop where I want. I can wild camp without worrying about juice. At campsites I don't have to worry about "losing" my powerbank or charger at public sockets.
My last tour from Holland to Ireland & back again was entirely self powered. I left fully charged and the one time I could have topped off from the wall (due to a very windy day) the very windy day resulted in a power-cut!
