Powerlifters catch flak all the time from gymrats and armchair quarterterbacks. Over the years I've had my share of "I could lift that in Highschool" and "I can Bench that!" scrawled across my comments section. Ultimately, strength athletes are almost exclusively in competition with themselves, always trying to 1-up their numbers... meaning, we don't give a dang what you think.
Here's the thing... most people crack under the pressure of competition... that's why so few ever step on the platform.
On top of that, there are a ton of things that go into training for a competition. Getting yourself a gym PR on any random day when you're feeling strong, after a good night's sleep, and with enough pre-workout in your system to explode your kidneys is what we call a "statistical anomaly"; it is a random happening (and unpredictable). When training for a competition, you can spend months prepping for a single day, 9 attempts across 3 lifts...
...and then you have to take into account traveling hours to the meet, sleeping in a foreign bed in a lousy hotel, making sure you weigh in at the right weight, eating right while traveling and not ending up sick, warming up with 10-15 other lifters sharing 2-3 racks, and keeping fueled for an 8-12 hour lifting session...
Oh yeah... did I mention you're usually sharing a couple restrooms in a crowded gym/conference center with 60-120 other lifters all on high protein & caffeine diets. That's the real nightmare.
So if you want to show the world what you are capable of doing, get off your ass and do it. Forget your Insta-story PRs and your Box's PR board. Sign up for a meet and train your ass off. Get your numbers up on an official records page (like openpowerlifting) so when someone like me asks "how much ya Squat?", you can give an honest answer.