>I don't see how Roman gladiatorial combat is so different from modern sports. The only major difference is the fact that nearly all gladiators were slaves

How about modern sports aren't "to death"?

Whatever you think about the risks and violence of modern combat sport, they don't use the certainty of somne of the combatants dying and/or the involvement of the crowd in determining whether they had fought well enough to be permitted to live after defeat as marketing strategies...

Well let me know when sports stars sack a city and lead to massive damages and people still decide to keep on doing it that way. (Third Servile war - although slavery was involved.)

Although often well paid gladiators often were slaves which brings up the next big difference - consent!

> I don't see how Roman gladiatorial combat is so different from modern sports.

If someone were to properly incentivize you (say, by offering to give you $10000 or whatever) I bet you would be able to come up with few more very important differences.