Its the best we can do to show power at specific, replicatable scenarios. You can't take a random battle as evidence as there are other factors in play, for example if the enemy facing the JLI they have even more of an advantage because that unit will be sniped even quicker...
Putting JLI against Obers is not the 'best thing you can do to show power' when that matchup is completely unrealistic and serves no purpose.
If you want to test their strength, you need to put them in equal tests. I.E. put them in the exact same situation (upgraded, at all levels of vet, at all ranges and in all cover situations) against the exact same enemies (pick one squad like Penals) and test this multiple times.
If you do that, which I did, you'll see that JLI are 'only' at about 80% of combat strength of Obers in pure small arms engagements. And that is when JLI have the First Strike bonus advantage. This does not include the Obers' bundled grenade nor the IR STG44 upgrade that increase their combat power significantly.
I've done small tests with multiple types of engagements and the Obers are clearly better in all types of engagements with any level of veterancy, with only vet5 being anything close to equal.
This is the outcome of these engagements against a Penal squad in comparable cover at medium to long ranges. Note how the Obers barely lost any HP in these engagements (the vet3-5 squads were at 95% hp before they started healing) while most JLI squads took at least one model loss and a significant amount of HP. They took significantly longer to kill all enemy models.
This means that yes, JLI overperform for their cost a bit and that they should become ~280MP and 60MU but they are nowhere close to being "as good as Obers for 250MP". The main problem is JLI blobs, which should be solved by this increased cost and by increasing the cooldown.
All in all I think that people are greatly exaggerating how powerful JLI really are. There is a good number of counters. Overperforming yes. Overpowered no.