My local bike shop carried three different brands of Ebike, over a three year period, each of them for 1-2 years, stopped handling them altogether, then went out of business 2-3 years later. 2 of the 3 were of European origin, one of exceptional quality.
I chose my performance, abilities, accessories, style, and capability to match what I wanted. What other people thought was "cool" was simply not a factor, as my wants, needs, and desires were unique to me. Also, "most people" are dumber than a box of rocks.
$325 for motor, controller, and display. Latest battery was $225. Mounting the rear rack was the most difficult part of the entire installation. Motor is still available. Controller and display can be replaced with multiple models using same connections, originals are still available. Battery has no special connections or mounts, numerous replacements available. Original model still available. That is over a period of 8 years. Most commercial bikes no longer carry parts or provide service for bikes over 3-4 years old, often much, much less. Most of their replacement parts are more expensive than my entire kit. Substituting non-brand parts is sometimes just not possible, and if it is, requires significant re-wiring and configuration, often with significant loss of function.
Nothing in my kit requires any kind of setup, dealer diagnostics, or configuration, zero, zilch, zip, nada. It continues to function as intended, over 20,000 miles, mostly because it was chosen to do WELL, what I do with it.
Donor bike was chosen using same criteria and methods. I have replaced brake pads, tires, tubes, and changed the seat. All parts I could get at my local hardware store.
FIRST, define the job, THEN, carefully choose the correct tool for the job. If you have ever actually used one of the "tools" on a swiss army knife, ponder that experience for some considerable time.