I agree with the above statements regarding historical calculators may not reflect current or future scenarios. I'm also not a fan of/do not use deterministic calculators (e.g., i-orp) as I have no idea what returns will be in the future.
Back when I was comparing calculators, I found Fidelity's to be the most conservative. I still find Fidelity's calculator useful/instructive as it includes monte carlo results reflecting significantly below market averages, below market averages, and historical market averages. IIRC, Wade Pfau and Michael Kitces have posts indicating that MC scenarios are useful as guides in planning PF withdrawals. Regardless, the most important thing is to incorporate a margin of safety into all plans. Venture capitalists do this, as do Munger and Buffet who are strong proponents.
Examples of margins of safety in retirement planning could include, but are not limited to, saving more than retirement spending estimates require, eschewing debt (the bad kind), not buying a larger house than you need, frugality as a general principal, remaining flexible in PF withdrawals in response to market conditions, maintaining sufficient insurances account for deep risks, optimizing health, choosing the right partner in relationship (divorce can be costly/devastating to retirement plans), sufficient estate and disaster planning, etc.