Yes, it's better. I personally know a dozen or more people just in this little neck of the woods who've already had Covid TWICE. Meaning the first infection either didn't generate enough or ANY antibodies to defend against the same infection the second time. Already knowing that Delta is more infectious than the first brand we had, if it's something you want to gamble on, then that's your prerogative. If it were me, I'd surely at least get my antibodies checked and find out what numbers put you at a good level of protection against Delta.
As for flu shot, best I can understand they have to PREDICT what strain is going to prevalent each year and try to defend against it. Which is why sometimes the flu shot just "doesn't work." It's working it's just not looking for the right strain. I know that my own son has had 2 strains of flu at once before (which shocked me but I'm sure is probably common lol). The COVID shot (at least to date) is effective against all strains, and overwhelming majority of the time does it's job very well. Which leads me to...
Final point, it's not just about fighting off infection. It never has been. It's about fighting off SEVERE infection and death.