If you buy a proprietary ebike, you get a proprietary battery in most cases. So, in several years if you are still riding and you need to replace the battery, you are stuck with that manufacturer - nothing else will fit, and in many cases, the bike will refuse to work with a battery that doesn't report the manufacturer's little hidden code. Even if, electrically, your new battery would otherwise work - it won't.
Batteries are a major part of the expense for an ebike. For those of us who assemble our own (and therefore can't be held hostage to arbitrary pricing by a manufacturer) the battery is THE single most expensive component. That is part of why you can only use the proprietary battery on a proprietary bike. They want that money - there is a lot of it.
If they cease selling that model, you have a paperweight.
For this and other reasons, you will serve yourself well to assemble your own. With help. The skills you need to maintain your bicycle anyway translate well to what you need to assemble your own. You can easily pick up the rest here and from some other sources.
You will either save money, or spend the same to get the ebike of your dreams depending on your choices if you assemble your own.
And, you can upgrade parts of it over time if you like.
What existing acoustic bike (a joke - meaning non-electric) do you have or fancy now? That's a basis for working out how to put a motor on it.
