Have had more cartridge guns misfire than BP.
I will give you the benefit of the doubt in you having fired a lot more cartridges than black powder.
The issues with BP revolvers are simply added possibles of failures. The first round may fire and the 2nd may have a Cap lock. The first one may have the powder too compressed and the 2nd one fires, followed by a Cap lock.
I have had a lot of failures with BP so far. I found I can reduce them. The only one I think of as mostly reliable is the ROA.
I have shot a lot of cartridges over the years. I never had a failure (my 45 Star P{D actually fired Glock 45 ACP though it would not cycle). I put a 223 through an AK47 once (well my brother did but I handed him the gun - heard the weird sound and stopped - no idea how I managed that).
I found I was better hunting with factory cartdige than reloads, never had one mis fire. I did have mistakes on the sizing on reloads and too much head space and it would not fire.
BP Revolvers are a coin flip as to them firing or not. In theory, if you developed a load and were anal about how deep you seated it and tested it well, you could have a degree of reliability.
Putting all cartilages into a failure of Super Vel, hmmnm. Why any department would use those is questionable in and of itself. Super Vel was some stuff so hot it pushed the edges and beyond of rationality. I never had any failures to fire or blow ups but it was not anything I would use other than playing with it on a range. And no, none of my guns blew up. That includes a 25 ACP made in 1911!
So, cool to carry is a contradiction of the purpose of an EDC. If its about image you got an issue. But then I was never one of the cool guys.