Delta is known to be more transmittable, which means it can affect more people, and thus cause more deaths. Last I read, the statistics are still out on whether it's more likely to kill once someone contracts it. Part of the reason it's harder to tell is because the death rate is highly dependent on rates of vaccination and availability of health services (i.e. ventilators, ICU beds, etc), not just the virus itself.
Yeah, "is it less deadly?" is a complicated question, if only because whether you die depends a lot on what hospital resources are available.
An easier to use metric is that once you have the delta variant, you are not any more likely to need to go to the hospital than with the original strain. Delta is more transmissible, so barring vaccination, for the same human behaviors you'll get more infected people, but their individual chances of needing hospitalization are no greater.