I think we are talking about personal environments a bit interchangeably or confusing them with things like environments that are part of your CI/CD process like the “integration” environment and a “staging” environment. As a tester, your personal environment needs to be cheap and lightweight as possible and only needs to change over time to better catch any bugs that actually escaped.
The real world is often context specific and your context matters. Environments in many teams are often hybrid, where you don’t end up controlling everything, but end up sharing some parts. Sharing an environment can also be an advantage, especially if it makes you think about testing at scale more carefully if you have to share a resource. Private environments have their own disadvantages, I’m a fan of mixing it up.
I think to answer the question, “Should it be like production?” , that “Depends” is not a good answer. Mainly because it’s that trade-off of financial cost to copy production and how many more bugs that will actually help you to catch. It can lead to bikeshedding and avoiding the issue, and distract people from time better spent hunting bugs if your environment is very hairy. Generally it’s possible to catch loads of bugs in a much smaller and vastly-scaled-down environment, than in a realistic one.