OP, there's a pretty reliable way to check which games are worth getting in a given month: look at the Best Sellers section on the eShop and ignore all the games that are currently on sale w/ deep discounts (less than $5).
It won't help you find the best games from a few months ago, but it'll tell you where the system's pulse is at right now.
Have their been seven new first-party releases for Switch so far this year? I can't quite think of that many.
Kirby Star Allies
Nintendo Labo Toy-Con 01: Variety Kit
Nintendo Labo Toy-Con 02: Robot Kit
Mario Tennis Aces
Sushi Striker
Octopath Traveler
(Splatoon 2: Octo Expansion)
That's six games so far vs. six from last year during the same timeframe.
Coming this month:
Nintendo Labo Toy-Con 03: Vehicle Kit
(Xenoblade 2: Torna the Golden Country)
We also had one game in September last year, but it was a Wii U port.
Coming in Q4:
Super Mario Party
Pokémon Let's Go Pikachu/Eevee
Super Smash Bros. Ultimate
Vs. FE Warriors, Mario Odyssey, and Xenoblade 2 last year.
Plus we're getting like 3x the ports on top of that.
The quantity is definitely there; what's missing is the big single-player games of the variety we got last year. But if you factor in ports (all the first-party ports from last year were competitive multiplayer games, this year they're mostly single-player games), we're still getting lots of single-player content.