I guess the real question is what benefit is this To me or anybody else what is the purpose
Not sure what you mean?
Of things are going well for you , no purpose.
I hope to achieve something, for each of us the results, need or reason could be different.
One example, my semi-custom .280ai is getting an extreme spread in velocity of say 80fps, I would prefer that to be a lot lower and get a SD in single digits as I think I am doing each step of my reloading as well as I can with quality components.
Getting better consistency in velocity may aid accuracy
Crimping may aid neck tension, aiding a more consistent burn before the projectile moves. It might aid accuracy.
Some might seat projectiles out to the lands. That might cause high pressure s and not be desirable when remote , particularly on a remote hunting trip where things can go wrong or just can't rectify an ammo problem.
Jamming the lands might also cause a projectile to stay jammed (slightly) when trying to unload a live round if required. Back to no good out hunting.
Shooters with heavy recoil cartridges believe it's good practice to crimp to be sure projectiles don't move under recoil. Period.
Butter Beans example is ammo , projectiles moved in freight or within the magazine. Either cause he dropped out or under recoil , doesn't matter. It means they were not secure to start so seating depth could stuff up the hunt or range day, at a minimum it changed the dynamic s and consistency.
Many shooters have found used correctly (reasonable tension) it either aids or has no adverse affects.
It's a cheap tool only made offered commercially by one manufacturer, fortunately the cheapest one.
Some feel it's important in semi autos for reliability and keeping projectiles seated in high capacity mags.
I don't own much Lee gear but I'm hearing good things on some of it and at $15. US, it's worth a go. Even if only on some cartridges.
I'm paid about $40 AUD delivered each for some on eBay yesterday.
It might fix my load issue , one that I believe is related to neck tension. This in effect is putting tension via a crimp but not increasing neck tension in the way correct sizing or seating does. It's an extra step and different proccess to only crimp on the tip of the neck of a loaded round. Technical term explained earlier by others.
It can motivate some issues and does not seem to create any issues.
The only downside is being an extra step it takes extra time, minimal and negligible if you are just loading 50 rounds to hunt. Well worthwhile if it negates any negative impact that happened by not doing this.
Being in the field when you realise things have shifted could really mess up a trip.
An alternative to get more tension is a bushing die in either Neck or FLS, they cost a lot more and require one or more seperate bushings to be purchased. These are best used with cases with a consistent neck thickness done as an extra step on extra equipment, this is not going to crimp but it allows more control of the neck tension or more tension as required in the regular way.
Crimping might be a simple solutioun to aid tension , consistency and accuracy potential depending on your ammo and requirements.
It might be a Band-aid solution but it might have its merits for handloaded hunting rounds alone.