Jobs advertised as remote are often not globally remote - as in, there's an expectation that the person they hire will be in the same country. If you're applying for US jobs from a developing country you'll probably get a different response than a developer based in the US (or no response at all).
If that's not the case, and you're a US based dev applying for remote jobs in the US, then there's probably some red flags on your resumé - impossible to know without seeing it.
17 years experience / late 30s doesn't put you in the ageism bracket.