Depends a bit on your goals.
Generally though I would say stoke that ambition to sell to your top picks. That way you are incentivised to improve your writing - aim to get something from them. Yes if that fails, work your way down, but I'd have a cut-off on where to go next and try and go for 'significant' ones. i.e. ones that definitely pay or have some sort of reputation.
The law of diminishing returns kicks in - you have only so much time to focus on writing. Perhaps you are producing quality writing and you just haven't caught the fancy of editors*. Well then just keep plugging away sending stuff to the top end of your list. Sheer bloody-mindedness is a good quality for an author, IMO.
However, it may be that going deep down into the 'rags' actually just wastes a lot of time, and please pardon the French, has you polishing a turd for an outlet that will not give you anything and as is read by no one, gets you no reputation either** ***. In that case you really need to be doing is improving your writing craft, and getting round to writing a better next generation of stories. Don't be afraid to abandon your babies.
--------------------------------
* How do you know if your writing is good but your not getting any feedback from sending stuff in? Try and get high quality beta readers who will properly criticise. Best to have those involved in the publishing industry, otherwise utilise critique sites - such as ours, but there are quite a few other ones that are good.
** If you do end up at the bottom of your list (plenty of places will take your money rather than the other way round!) it may be that you are just not good enough - so the system is likely telling you to improve! Which can only help you in the long term. A bit of honesty helps the author also!
*** However it may be beneficial to go through a publishing process, even for a 'low pick' just to see what it is like and gain a bit of experience of publishing. (and to get a little thrill from actually publishing.) Watch out for sharks of course...
