Then there's the counter-argument that within reason having a low level of infectious diseases hanging around isn't such a bad thing. It trains our immune systems, preparing them for more serious attacks. I honestly don't know how good an idea that is, but it seems plausible and Ive heard it from medical professionals.
At the medical science level, we absolutely do investigate common cold pathogens and others, and have developed a battery of techniques, all of which were very rapidly brought to bear on Covid-19.
Where I think we do need to do a lot better is in international co-operation and co-ordination. In the USA the CDC needs competent leadership again, they need their seat back at the US national Security Council and they need their international outreach budget back. Europe needs to develop their own equivalent to the CDC that's well funded and effective.
The WHO also needs thoroughly upgrading. I think given the way national governments have ensured the WHO stays a political football, they actually overall do a lot of good. A lot of nations are thoroughly reliant on them for advice and technical assistance, but clearly their chronic dependence on the good will of nation states has severely compromised their ability to act as an independent and effective organisation. They need more funding and more independence, not bullying by China and the USA to serve domestic agendas.