My grandfather, WWII vet who recently passed adored the VA wherever he lived and refused to see private doctors, always choosing the VA and from our POV they always did the right thing by him.
I had a friend of that generation too, he just passed away this year at the ripe old age of 99, and he had nothing but good things to say about the VA.
Conversely, my partner, and her brother, both US Navy vets in their 40s, they have mixed things to say about it. They both would agree that it's "better than nothing", they both say it has provided a great safety net for them and allowed them forgo caring about health insurance when looking for jobs, yet neither is fully satisfied with it. When it comes to primary care, preventative medicine, things like that, the VA is great, more or less the equal of what I get with my platinum plated private insurance. When it comes to speciality medicine, it's hit or miss. The wait lists are the worst part, it takes her weeks to months to get an appointment with her regular care team, diagnostic tests, etc.
My beefs with the VA, as someone who has loved ones in the system: It's absolute garbage at dealing with mental health, which you'd think would be a major focus for a health organization that is supposed to be treating veterans. I have never gone to the VA ER and not seen multiple patients with major and apparently untreated mental illnesses in the waiting room. My partner had to resort to self-paying private practitioners to come to terms with her mental health damage from combat deployments, because the VA was useless in this regard. If you aren't suicidal and/or easily treatable with meds, they got nothing to offer you but wait lists and bureaucracy that would make the worst HMO look like concierge medicine.
That brings me to my second beef with the VA, it has no equivalent of Urgent Care, at least in the major metros we've called home, as well as those we've been unlucky enough to be traveling through when my partner had a health scare. You either get an appointment with your regular care team -- which will probably take weeks to months -- or you go to the ER. None of the scares my partner has had in the four years we've been together have been "ER worthy", when the equivalents happen to me I go to Urgent Care, but she has to go to the ER. Not only is this stupidly expensive (shouldn't the VA want to save money where it can?) but it invariably leads to insane wait times. Something I could get knocked out in an hour or two at any Urgent Care Center is probably going to entail six plus hours at the VA ER.
I should also add "They have too many Dr. Feelgoods" working for them. My partner was on an opioid cocktail from the VA to manage service related injuries. It took her years to wean off those drugs, against the advice of her VA care team. Now she manages with weed and the occasional NSAID, so did she really need to be on opioids? They gave her zero help weaning off them, in fact, they tried to discourage her from doing so. They still throw major controlled substances (ambien is my favorite) at her like they're candy. If there's a Schedule II or III drug you'd like to get, just sign up for the VA, you'll find a provider willing to write you a script in short order.