You mention buying the highest capacity batteries you have found. They might be great for flashlight where you want to use them for few weeks*. However, if you want to use them for something like one year without charging, highest-capacity batteries are likely not the best choice. I have both an anecdotical evidence (cheap IKEA 750mAh batteries outperforming 950mAh GP) and theoretical explanation.
Anecdotical evidence: I bought few Styrbars. Most of them got new IKEA Ladda 750mAh AAA batteries. I didn’t charge them before use, so they have started at about 85 %. One Styrbar got 950mAh GP ReCyko+ 1000 AAA batteries, 100 % charged. I expected the GP (fully charged and higher capacity) to last longer than the Ladda (partially charged and lower capacity). At the moment, all Laddas show at least 75 % (with short temporary drops to 70 %), while the GP shows just 30 %. Note that the comparison is not scientific, the GPs weren’t new (but I don’t expect them to be that worn out after just few cycles) and the usage frequency also differs (but this probably rather favors the GPs over Laddas).
Theoretical explanation: Low self-discharge NiMH batteries need a stronger separator, which takes more space. For this reason, they can’t achieve as high capacity as high self-discharge batteries. So, when you buy the highest-capacity batteries, they will likely have rather high self-discharge.
Also, not all LSD batteries are equal. Eneloops have a good reputation for being ultra low self-discharge. However, there are some other brands (including IKEA) that seem to be just rebranded Eneloops, sometimes for much lower price: https://eneloop101.com/batteries/rewrapped-batteries/
And even not all Eneloops are the same. Some are from Japan, some are from China, and it seems to matter.. Also, they vary by capacity, and higher capacities have probably higher (though still reasonably low) self-discharge.
In Czech Republic, I’ve bought IKEA Laddas from Japan, both 750mAh AAA and 1900mAh AA. They are quite cheap (129CZK / ~$5 for 4 batteries). I haven’t tried the 2450mAh (more expensive and probably higher self-discharge), but they are reportedly exclusively from Japan. However, on some other markets, you might find batteries from China. Also, you can ignore sentences mentioning Sweden:
Using NiMH batteries when manufacturer recommends non-rechargable batteries can affect the estimate of battery percentage. This is fine for many devices, but not for those where accurate battery percentage is critical, e.g., smoke detectors. I have shared some more thoughts on battery status recalculation for NiMHs: NiMH battery percentage recalculation
*) And even with this use case, it might be a good idea to check (and potentially recharge) them even twice a year, even if you don’t use them, in order to prevent damage caused by deep discharge.
EDIT: Fixed the capacities of the GP batteries + a typo