HN has this understandable infatuation with startup mode, but running a truly global product line of anything with a large customer base is simply a lot of work.
Apple can't be run with 5 people, it also cannot be attacked by a 5 people startup. Same for Microsoft, AWS, ... broad massively multi-product companies are very hard to take on if they have their general shit together. Ask Slack how it went against MSFT Teams, a clearly INFERIOR product. Microsoft out-scaled Slack, simple as that.
Sustained innovation of a big company is a formidable moat against disruption. Look at big pharma, these companies have been around for 120+ years! Merck was founded in 1891 (from a root company founded in 1668!) and is still a 50bn revenue behemoth. And yes, modern biopharma is big tech.