I understand altruism to be about helping people, trying to make people's lives better in whatever way I can. This does tend to involve some amount of sacrifice, but if I could have a larger impact with less sacrifice that would be a good thing. In fact I choose my altruistic activities to do as much as possible with as little sacrifice as possible. So reactions like this confuse me:

For me, altruism should involve more than sparing the poor a few crumbs from our table. It should be about changing our behavior and trying to be nicer to the people we find most irritating. Peter Singer's Effective Altruism doesn't address this aspect of good living at all. His movement is just about doing stuff with money. It's a cult for wealthy middle-class Westerners who don't want to change their behavior but feel a bit guilty about the comfort they live in. The Effective Altruism movement allows its followers to continue their privileged existences—they buy themselves absolution by signing a direct debit docket to one of the EA-authorized charities. True altruism involves self-sacrifice; Singer's altruism involves salary sacrifice and nothing more. (source)

If I were talking to this writer in person I would suggest we taboo the word "altruism" and talk at a lower level. They would probably expand "altruism" to something like "making substantial sacrifices for the benefit of others" while I would expand it to just "working to benefit others". We could go on from there to discuss why they think "making substantial sacrifices" is important in and of itself, to the point of not valuing an approach that "involves salary sacrifice and nothing more." Maybe we would reach an agreement, maybe we wouldn't, but we'd get closer to understanding what we disagreed about.

As participants in a broader discourse around "altruism," however, we should push for an understanding of the term that isn't about giving things up. Someone who reduces their income to the level of world per-capita GDP or works in 100 degree temperatures hand-delivering meals to homeless people is engaging in intense self-sacrifice, but what matters is how much they're helping.