You've not mentioned the i]paper[i] that you're printing onto, which is usually FAR more important than the brand of ink you use. I've just printed out a portrait photo on my new Canon MG5750 printer, using the Canon inks that came with it, and compared the result to that which I got from the same photo a few weeks ago on my old MG5350, when I was using inks from Inkredible. (They were both printed onto HP Everyday Photo Paper). They look identical to me.
However I've learned over the years that cheap photo papers simply aren't worth buying. Irrespective of whether they're used with 'original' inks or 'compatible' ones, the results are always vastly inferior to those obtained by using a good quality photo paper. (Morrison's own brand photo paper is appalling, as is the stuff sold in Poundland and similar discount stores. Many other cheap papers aren't worth bothering with either). HP Everday Photo Paper is what I use for day-to-day photo printing, with Kodak Ultra Premium being used when, say, I want to frame a photo as a gift for a friend.
Similarly, when printing text documents, if you pay two or three quid for a ream of paper you'll never get proper 'office quality' from it. However using something like HP Bright White (90gsm) paper will always produce 'professional' results.
When the Canon inks that came with my new printer run out (which they'll do very soon, because I've printed quite a few photos recently), I've got some compatible inks (from Inkredible) already lined up for use. At £12.41 for a full set of five cartridges (with discounts available for bulk buying), I'm saving 80% on the £63.24 I'd have to pay for Canon's own inks. As I wrote above, I can't see any difference between the results I get with decent 'compatible' inks and those I get from 'originals' (as long as I use decent paper to print onto).
I note, Bainbrig, that your printer uses the same inks as mine does, so the prices I've quoted above will apply if you also decide to order from Inkredible. (I've been using their inks for years and I can thoroughly recommend them):
https://www.inkredible.co.uk/canon-pixma-mg7751-ink-cartridges
(I note though that there's also a sixth, grey, cartridge available for your printer. I've not encountered that before!).