This especially (in our experience) goes for partner-facing LoBs. Like a SaaS for your business partners, clients etc. A large companies might have 1000s of these. We get clients with 'so we have 600 applications and something is wrong with many of them after xyz'. These apps usually don't update ever but they are vital for departmental workflows and they are complex enough not to bin them and rewrite them (especially in these quantities).