Welcome to the forum,
@CosmicClayton. Good set of priorities, those, and refreshingly sensible for a first post.
Here's the honest situation: your combination of requirements (Bosch CX, 750Wh+, under $6,500 USD) is genuinely tight. Most Bosch bikes with proper battery capacity sit above that threshold once you're in the full-trail-to-enduro category. That said, there are options.
Trek Powerfly+ FS Gen 4 is the one I'd point you at first. It gets Bosch's latest CX motor and an 800Wh battery, with updated singletrack geometry and 120mm rear / 130mm front travel.
Prices for the Powerfly+ FS range start from around €4,499, which puts the entry models well within your budget in USD terms, with the top-end FS 8 pushing closer to your ceiling. Trek also has one of the strongest dealer networks in North America, which is exactly what you want when something inevitably needs attention.
The full-suspension models are also compatible with the Bosch Range Extender, so if you ever want more range it's a bolt-on rather than a new bike.
On reliability specifically: the Bosch CX is the most widely used full-power motor in eMTBs and is a mature, well-rounded system. Bosch's advantage is scale: a huge dealer network, Smart System compatibility, and a clear cadence of updates.
For someone who puts serviceability high on the list, that matters more than chasing the latest motor.