The certification discussion usually raises hackles among security people. I've been in infosec for over 20 years, so take from this what you will.

Question is what kind of work you plan to do. If you are contracting, most public sector contracts are awarded on a points scoring system that gives points for certifications. Given the value of a given contract (e.g. say, ~$200k for a year) paying for a $5k-$10k option on all of them is a sound bet. Other things could tip a points scale, but this is the advantage is what you pay for.

From an economics standpoint, demonstrating differentiated skill is hard. In the jargon, it means signalling costs for competence in security are very high. Many people use papers, blogs, conference speaking, exploits, open source contributions, and media hits to differentiate themselves, and the work that goes into this is more than most normal people put into their careers. A certification doesn't get you the same thing, but it will level you up to a point where many customers/clients are indifferent to the extra value implied by other peoples high cost signals. Is it an honest signal of skill or technical capability? No, but it's sufficient for most procurement cases.

The market (and the ISC2) has tried (and largely succeeded in it) to make the CISSP a bar to entry. It sounds from the OPs post that he is an individual contributor (IC) (instead of a manager) who wants to get into security because it is an IC role with a better future for an older worker than devops.

Realistically, a Masters in information security (distance education on this galore) is sufficient for a drop-in director of security role, as the role is mainly about navigating a large organization and buying technical talent as-needed. I would say having serious technical chops will differentiate you among security pros, where the market has become flooded with non-technical audit and governance people whose role is as an organizational gatekeeper.

Some amazing technical security pros will scoff at this, but what most people don't get is there is a point of diminishing marginal return on technical skill, where the only people who can even begin to appreciate your skills need to be at least half way there, and coincidentally, employers can't tell the difference, and they are a lot cheaper than you are.

The professionalization of the field has meant a new class of administrators will just buy tech expertise when they need it, and operate largely by trading on their political veto (the black box of risk) in their respective organizations.

If you are a technical IC who wants to rebrand as a security technical IC, it's interesting and challenging work with a great culture around it. However, be aware that given the expense and demand of it, the market is being flooded, and my recommendation would be that the longer term game would be to use it as a lever into a general management (or at least SE) role, one that you can still find work in when you are 50.

In answer to your final question, get education that is portable that you can leverage into that general management role. So again, Masters of infosec will set you up for a role you can do when you are 50, whereas technical courses only have about a 5-8 year value horizon.