I learned a hard lesson a long time ago. If you don't answer people's feedback, email, messages, etc they will get annoyed and not think about you and your products in the future.
This seems like one of those "duh" that's obvious things, but I can't tell you how many companies, teams, and individuals that fail at this every day. I experience a vendor, a potential partnership, or other inquiries I send out almost every day that go weeks or months without reply; sometimes nothing comes back at all.
It seems still incredibly relevant and one of those mandatory things you should excel at.
Now, I'm not perfect, by any means... especially as I stretch myself thin in this era with many companies and products.
But a few tips:
Setup Muse, Grok Bot, etc to scan your emails and summarize for you at least once a day (though I find twice a day helps), to bubble up things you need to response to in your email accounts
Setup an AI agent to auto-respond for you, at least to do an initial pass and get clarification or at minimum acknowledge the user
Automate as much as possible (you could have common tasks done automatically)
At the very least... DO NOT IGNORE the people that write you.
Even if it is a colleague, a random user, or yes, even a competitor. You don't know WHAT you could be missing out on.