ebike help

I am new to ebikes but I have always been fascinated with them and I truly appreciate what they offer in terms of making biking more enjoyable. I am more interested in mountain bikes. I have had a Spark 960 for a few years now and absolutely love it. I primarily ride it on paved trails but sometimes do unpaved and rocky trails but nothing crazy. I always wanted to do a true offroad trail but never got a chance. I am turning 40 soon and would like to start looking after my knees a little bit so the pedal assist seems very tempting and I think it might even motivate me to go on more challenging trails with decent uphill. So having said that, I am confused as to which one to get. I like the idea of having something with similar specs as my spark 960 with an electric motor. I see other options like the Happyrun G100 for example which is more like an electric motorcycle, seems very affordable but I am not sure if I can really take this to the trails and have fun with it.

If I look at pure pedal assist electric mountain bike options like my spark 960, they are pretty expensive. But something like a happyrun G100 is relatively affordable. So my dilemma is whether to keep my Spark 960 and buy something like the G100 which will allow me to have the best of both worlds or trade in my spark 960 to get an actual electric mountain bike from traditional bike companies like Scott/Trek etc. Also obviously worried about the quality of a cheap bike like the G100 from a non traditional bike manufacturer. It's just a very hard decision to make. Hope y'all can guide me in the right direction.