IME, you can use 3.3V logic with 5V WS2812B/SK6812 strips, no trouble.
Each LED reforms the signal before sending it to the next LED in the chain, so voltage dropping over distance shouldn't a huge issue for the logic line unless the strip is very far away from the controller.
And the datasheet almost agrees with my experience; the "high" voltage threshold is listed as 0.7×VDD, and 0.7×5=3.5V. That's a bit over 3.3V, but I haven't had any issues across several projects. Maybe it's because many USB supplies provide a little over 5V to account for droop? Maybe the datasheet is slightly pessimistic? Maybe 0.7 really means 2/3? Whatever the reason, it simplifies the wiring for small displays.
Here's my favorite reference for the single-wire protocol that these LEDs use, since everyone seems to be chiming in with one:
I think maybe folks got the model number confused. There are strips where the entire signal is passed verbatim without being reformed to every package on the line, but everyone stopped using them because they're awful.
In my experience, slow microprocessors are WAY more tricky to deal with than a 3V3 logic voltage for these strips; and often lead to crazy hacks. I'd way rather just put a modestly powerful resistor or a buck converter in my project than deal with trashy old Atmel chips, given how absurdly cheap ESP32 and ARM M7 packages are.
You'll get there! :)