Free providers have limits and this new time limitation will also play into that as there will be many more certificates to renew.
Large companies will keep on using paid providers also for business continuity in case free provider will fail. Also I don’t know what kind of SLA you have on let’s encrypt.
It is more complicated than „oh it is free let’s move on”.
Most every modern "big company" I have worked for is leveraging LetsEncrypt in some capacity where appropriate; some definitely more than others. I don't think you're completely wrong but I also think you're being a bit dismissive.
Large companies will keep on using paid providers also for business continuity in case free provider will fail. Also I don’t know what kind of SLA you have on let’s encrypt.
It is more complicated than „oh it is free let’s move on”.