I set up SPF, DKIM, DMARC, not on any public blacklists (confirmed through https://multirbl.valli.org/ https://multirbl.valli.org/), whitelisted by DNSWL.org at

I set up SPF, DKIM, DMARC, not on any public blacklists (confirmed through https://multirbl.valli.org/ https://multirbl.valli.org/), whitelisted by DNSWL.org at medium trust level, never sent any bulk email, and I had constant deliverability issues with Outlook and Gmail. Both of our experiences might be true, but yours does not invalidate mine. Simply setting up SPF and DKIM is not sufficient to ensure deliverability.