Just paid 3.6M Sats in one payment via Lightning, went through in the first try. It's all about channel liquidity.
Discussion
The network is very different than one or two years ago. There's a fair share of monster channels around, so if you also have a few in your node, there are good chances these sizes will go through.
How much was the fee? How many hops did the payment take?
5 Hops for 3571 Sats, not cheap but not bad either.
Wow, 5 hops! Very impressive. That's ~1k ppm fee, still only 0.1% of the payment amount. I would say not bad either 👌 More impressive is the 3.6m amount! A bit pricey when compared to on-chain fees. Still, average channel is 7.48m sat & median channel is 2m sat according to mempool.space, your payment was ~50% of average channel size! (& almost 2x the median...)