I can't remember whether I watched the 1964 national party conventions - I was eight at the time - but probably I saw pieces of them. In 1968, I watched most of both of them; I specifically recall sitting down with big bowls of popcorn to watch, and both were rewarding entertainment.
Every four years since, I have made a point of watching at least most of the two conventions, including the acceptance speeches and the keynote.
I watch them on C-SPAN, so I can get them clean, no talking heads informing me minute by minute what I should think about what I'm seeing.
Probably most people don't find these things entertaining (but then, reality shows are the depths of boredom for me). I still do, to some extent. But the main reason I watch them, and I'd urge other people to watch them, is this: The conventions are the place where each party, without interference, gets to make its best case for why you should vote for them and not the other guys.
Too many people contain themselves in little media bubbles, absorbing views and messages and information from one side or the other. Watch both conventions, and the debates in the fall (I like to watch debates from around the country on C-SPAN too), and you can fairly say you've heard from both sides, that you're not just listening to one.
This year, some Republicans might complain about that. Donald Trump took over that party and its convention, and many long-time Republicans, elected officials and others, were not part of the mix. Their voices weren't much heard (the main sort of exception being Ted Cruz). That's true. But it's also true that Trump has taken control of the Republican Party, for the next few months at least. And what emerged from the GOP convention was what he and his people wanted to say and wanted Americans to know about them. watch the convention, and you've heard their case.
The same is true on the Democratic. If you know someone who maintains that the Democrats want this, or oppose that, tell them to watch the convention, and that will give you a fair idea of what they and their presidential nominee do and don't support. Not all of it will match up with the bubble on the right, just as not all of Trump's convention matches up with the bubble on the left.
Day one of the Democratic convention went, from the viewpoint of a remote watcher, generally better than most media reports seemed to indicate. Bernie Sanders backers, understandably infuriated by what the DNC leadership has been up to in trying to undermine their campaign, made their views and occasional displeasure known at the beginning of the day, and after Sarah Silverman's challenge to them in the evening. (That wasn't such a wise move.) But the speeches mostly moved fast, strong, and varied. Michelle Obama, Elizabeth Warren and Sanders finished the day effectively, and my guess would be that after the vote today, the convention calms down.
And then, both conclaves under our belts, we can go on and absorb the next 100 or so day, and vote.