Opticallimits

ilford HP5  SLR scanned with 750D plus 100mm macro (dunno if it was perfectly done) versus 5D converted via DXO, adjusted to taste

1. HP5 plus for 135 format is a bit grainy. I suggest T-Max400 or Ilford X-P2. 
   
2. it's very clear you didn't adjust the "scan" and went with your "adjusted to taste" of the DSLR version a very contrasty way with poor shadows.
   
3. if film is your thing, get a medium format camera with a decent lens if you want to get close to what DSLRs can do these days
   
4. it's just a terminological thing: You don't call macroshots scans.
   
5. For scans you take scanners, hence the name. These scanners lack of a hardware moiré-filter and get out the maximum of information, while your canon has a filter in front of the RGB sensor. You can run a scan for grayscale only, so you have no loss due to interpolation of RGB pixels.
   
6. The lighting behind the negative also is critical - you cannot have both, usually: good ad balanced contrast or maximum reolution and sharpness. See for "condensor" and "diffusor" light heads of enlargers. Diffusors are less critical for small dust particles because they caus a certain softness. Condensors bringt out the last detail - of hairs, grain, scratches and dust.
   
7. And the smaller the film format, the more perfect your scanning/macrophoto process has to be.