It probably is hard and intensive. Engineering shouldn't lie and promise that it will be easier. Product has to take that engineering estimate and determine whether to work uptime or some sexy feature (and sexy features usually win because of perverse incentives).
Moreover, I have a hard time believing this for a couple reasons: first of all, I've scarcely met engineers who were opposed to improving product reliability, maintainability, etc. The portrait of Google engineers arguing that database services fundamentally shouldn't be HA (and customers are "using it wrong" for wanting HA DBs) is particularly incredulous. Secondly, I've never heard of an organization where engineering held political power over product decisions, but I have worked in several places where product dictated engineering solutions. Businesses trust product more readily than engineering because the things that engineering is always petitioning for are abstract and "costly" (deferring some immediate profit for reduced costs in the long run) while the things product wants are usually tangible and profitable.
If product has PM or financial incentives that reward without regard to technical debt...
If engineering has PM or financial incentives that reward without regard to user experience...
If you want people to cooperate, set up shared, team-based incentives!
I haven't worked inside AWS or GCP, but I've never seen product get everything they want, especially around maintenance/downtime. If "less downtime" is on the roadmap but engineering is constantly pushing back "that'll be really really hard and take a long time and they're just using it wrong anyway," I can't imagine it getting done as quickly as at a place where the engineering team was also focused on customer satisfaction.