look in the mirror!
Almost everyone can get stronger, regardless of ailments and age.
Exercise is one of the best things for MS and many many other diseases. Well known facts.
MOST of what we percieve as a results of aging are in fact results of DIS-USE as people stop doing things because they are getting old.
Research clearly shows that at ANY age (90 y/o's too) we get much much stronger with any amount of increased muscle work.
So lumping everyone that's aging (Im 58) and has problems (2 torns acls, 2 torn rotator cuffs, none fixed surgically, repeat stress fractures of the feet, ankle problems, etc) with you and your heart problem (I'm sorry) is not just grumpy and downer, it's plain wrong.
Secondly 'stronger" in biking terms doesn't just mean strength. there's strength of riding skill, knowledge, using the gears correctly, etc All MUCH more important on a mid drive with it's power than on a hub drive.
Were you a biker before the Ebike? Many were not and need to learn to use the gears.
Bigger, stronger hub motors lead many riders to lean on the motor instead of shifting gears as you would on a regular bike.
If you do that with a mid drive bike you WILL be working harder than you have to as the motor won't make up as much.
What's your cadence? based on the gearing the rpms you are spinning on the pedals mostly determines your heart rate. Spinning fast in a higher gear keeps the load light and heart rate consistant. Mashing (pushing hard and slow rpm) works the muscles much harder, requiring more blood flow and thus greater heart rate swings.
If you don't know those things, there's a night and day difference to be had as you learn them.
If you know those things, you'll use them and come to like the mid drive biking experience much more.
If it's an off road bike like my Hai, it's geared VERY low and simply gearing (changing cassette or front ring) it up to be able to pedal at higher speeds is a great help.
All those things make it likely you can get your HR down where it needs to be for you.
You are right about the good in getting people out.
Just stop shorting them (and you?) in what you can really get out of it if you put into it. (to the best of our ability)