We have pretty different views on tech elites. I don't think they are evil per se, but most are greedy and generally lack empathy. It's almost impossible to go from mildly wealthy to multi-billionaire status without some aggressive wealth accumulation.

For the philanthropy, I'll just note that these pledges don't involve literally transferring 99% of wealth out of their control. The vast majority of the pledged money goes to a trust the person controls, organizations they have some relation to, or just stay completely in their control for years with only vague non-binding commitments to eventually donate it. In return for this largess they get significant reputational and tax compensation.