Jack of all trades - Does being one hurt or help?

Being a jack-of-all-trades could be either.

• It hurts insofar as you are unable to develop a "brand" as someone who's an expert in an area. To get promoted to Staff or beyond, you really want to have a thing which people say "For that, this person knows the most" (you want to the be person)
• It helps insofar as you're able to provide value quickly to many people. You build a strong network of advocates if you make their lives easier.

If you're earlier in your career, my strong recommendation is to focus on depth. Just master one technology or framework and answer any question about it: This Is How Software Engineers Should Initially Learn.

Two related discussions:

• I really like the answer from Lee here: How to balance between specialization and pigeonholing?
• Breadth vs Depth as a junior engineer?

what if these org/pillar/domain hops were across a few companies

I think it's totally fine to switch domains, but the bigger issue IMO is that career advancement will be quite difficult at the Staff+ level if you job hop so much.

See the blog post: Strategic Job Hopping: How to Leave a Job Without Hurting Your Career

@Rahul, what if these org/pillar/domain hops were across a few companies, not in the same company, while staying at the same staff+ engineer level (lateral hire into a different company) ?

It depends on your style. I have seen many several Staff+ engineers succeed in both ways (specializing vs. spreading out). At the end of the day, I recommend striving to fill in the gaps - Find the biggest problem or missed opportunity in your organization and solve it.

From there, see where that takes you. Maybe the biggest gap requires you slotting into the fixer/solver archetype. Maybe it requires you to code across 3 different tech stacks. Maybe it requires the generalist/tech lead archetype.

What I will say though is that job hopping will hurt you a lot as a Staff+ engineer, similar to what Rahul said. At that level, you need a lot of business context and product intuition to continue finding large scope.

Here's another good discussion about this kind of behavior: "What makes a staff engineer from a technical perspective?"