I don't disagree with you but I think people also need to understand that management often pick the team that provides lower estimates because team members will have to work harder to deliver it.
Management might not be so dumb. If someone said 2 months and you say 6 months, they might go with the person who said 2 months but will accept 5 months secretly.
The 2 month version experiences scaling issues at a 20% rollout, or takes 20s for a database query before returning a page.
In 6 months you need a better scaling version while the current version is creating cascading database failures; it's got terabytes of denormalized data that is out of sync and a 2nd team can't migrate the data in 12 months.
In 12 months, you find 5 other teams copied the 2 month solution.
In 2 years, you have 0 devs left that can solve the problem and a 1000% grown dev team that is great at the 2 month solution.
You ask the teams why they don't use the scalable solution and they say, "do we have any examples of that, the unscalable way is our convention"
Management might not be so dumb. If someone said 2 months and you say 6 months, they might go with the person who said 2 months but will accept 5 months secretly.