...should I carry on with that or try and find a good kibble? (obviously the latter is easier and less time consuming)......
Hi & welcome
Difficult to answer the question without knowing
(i) What products you would regard as a "good kibble"
(Ii) How much you are prepared to &/or able to daily spend.
(Iii) What your home cooked diet consists of.
Without wishing take your question too literally......there isn't a turning point where a kibble is classified as "good"
This site should, however, open your eyes beyond supermarket value choices & hopefully give you some better options within a specified budget.
If I was after a better kibble than Asda Hero & on a tight budget then I would seriously look at Autarky or Skinners products as at an acceptable quality & price start point. That said, even these are roughly 2 or 3 times respectively more costly than Asda Hero.....a product which I personally would never feed. I prior considered feeding autarky salmon & have fed Skinners F&T Duck & Salmon varieties. It would pain me to buy lesser quality cheaper foods but do see paragraph below.....
.....If budget was truly tight I would maybe consider CSJ Hi Lost formally branded "That'll Do" £12.60 for a 15kg sack. Not saying it's the best kibble by any means but probably better than the kibbles you have been feeding. Factor in postage at £6.85 for 30kg and it works out at £16.02 equivalent for a 15kg sack delivered if you buy two at a time. CSJ champ comes in at £11.50 per 15kg so £14.92 per sack if you get two at a time........ I would usually be reluctant to recommend a food I have not fed, however, a local show competing Great Dane breeder told me he happily feeds the Champ without issues, (known to him). I think you will struggle to source better or equivalent food for the same money but do bear in mind that as quality goes up the daily feed weight can go down, ( the maths isn't as simple as calculating pence per kg). Be mindful of that on both these CSJ products "meal" is listed as the main protein ingredient. The percentage breakdowns are also not clear.
Whatever you decide, I strongly urge you to look beyond supermarket shelves if looking for a more acceptable dog kibble. Prices can vary between online suppliers & independent stockists so do shop around once you have selected potential replacement foods. Don't forget to consider postage or travel costs to collect.
You can spend more & in doing so arguably buy better, however, you could also spend more on products that are arguably inferior to my carefully cost factored suggestions.
I currently feed raw complete products. I only felt need to mention this as I do not currently feed any of the products I have suggested you may wish to consider with others.
Bear in mind that what might look ideal on paper or screen might not suit your dog. If switching do consider a meaningful trial period giving consideration to appropriate introduction & adjustment until best feed amount ideally ascertained.