I will echo that if you don't care much for the plot and the dialogue, Octopath Traveler is a very pure turn based RPG with a great mix of mechanics from other games, namely Bravely Default (Brave/Default), FFV with the jobs and sub-jobs and maybe even some SMT with the Break system mimicking weakness targeting and Press Turn.
Mechanically very fun, although the only challenging bits are the boss fights and quest fights, unless you walk into a field of high level mobs unprepared (which happens unfortunately).
Fire Emblem Three Houses has A LOT of fluff to wade through inbetween battles - I personally am a sucker for all that fluff and specifically grind stuff just to see MORE support scenes, so I can't attest to it, but you could theoretically skip most story scenes, and use the fluff academy part simply as an overly complex menu where you decide how to build your units and manage your inventory.
The game is very forgiving since it has a mechanic to take back turns that didn't go well for you, so it's not the worst entry to get into the series with and try the mechanics.
People that claim that it's one of the more easy games definitely take this mechanic into consideration.
It's still not one of the more challenging or diverse entries in the series, but, eh, it's on Switch.
Xenoblade Chronicles 2 has a really cool battle system, but also a shit ton of other systems to take care of, and some RNG lootbox nonsense when it comes to acquiring Blades (special weapon sets). It's a lot. If you only want to play one JRPG for the rest of the year, you could probably deep dive into XB2 and the prequel/sequel Torna, and you'll have your fill of diverse mechanics, challenging battles and a whoooole load of JRPG nonsense and characters to top it all off.
Final Fantasy XII - The Zodiac Age on Switch (and Xbox) is the best version of the game to play (compared to PS4 and Steam) since you can reset your job board at any time, meaning you don't have to commit to one build for the whole game. It also allows you to switch between gambit presets you made. Personally I hated the combat (especially the stupid chaining, which seems like an excuse to make a maximum of 4 enemy types per region), but that's just me. A lot of it kinda revolves around programming your AI group members by assigning them gambits ("IF x DO y"-conditions), which can be really fun and puzzley? It's very unique in this sense, and allows for lots of interesting party combinations.
Concerning the story, I was not impressed (and lost interest SUPER EARLY), but the set pieces are very nice.
Upcoming recommendations:
Someone here mentioned Crosscode by the way, a Western made RPG with lots of JRPG-inspirations you'll enjoy. The Switch port was announced for this year, but it still has no official release date unfortunately. Another thing that's still a ways out would be Tokyo Mirage Sessions #FE Encore - the shortest way to describe it would be a "Persona Lite" with some puzzle dungeons, I enjoyed the battle system a lot, especially boss fights are pretty challenging. It does require you to have a high tolerance for saccharine J-Pop nonsense though. It comes out January next year.
