I tested my battery at three different shops and got three different results who should I trust?

I'm really confused and frustrated after spending my morning driving around Sharjah getting my battery tested. I have a 2017 Honda Civic and my car has been cranking a little slower than usual, so I decided to get the battery tested. I went to three different battery shops, all within an hour of each other, and got three completely different results. Shop one used a handheld digital tester and said my battery was at 85 percent health, CCA 420, and it was fine. Shop two used a similar looking tester and said my battery was at 55 percent health, CCA 290, and recommended replacement. Shop three used an old school load tester with a meter and a big switch, and said my battery was borderline but probably okay for now. Three shops, three different answers. How is that possible? I've been researching how to prevent issues with battery checks and I thought testing was supposed to be reliable. Now I don't know who to trust. Is one type of tester more accurate than another? Is the old school load tester more reliable than the digital ones, or vice versa? Could the temperature in the shops have affected the results? It was a hot day, around 42 degrees. Does heat make batteries test worse? Should I have waited for the battery to cool down? Also, I noticed that at shop two, the guy didn't clean my battery terminals before testing. At shop one, he cleaned them quickly with a wire brush. Could that have made a difference? I'm trying to decide if I should replace my battery or not. The car still starts, just a little slow. But I don't want to get stranded. How do I know which test result is accurate? Should I go to a fourth shop? Should I just replace the battery to be safe? That seems wasteful if the battery is actually fine. Has anyone else experienced inconsistent test results between different shops? How did you figure out the truth? What would you do in my situation? I'd love to hear from mechanics or battery experts about why tests can vary so much and which type of test I should trust the most. Any advice would be really appreciated because I'm stuck and I don't know what to do. I just want an honest answer about whether my battery needs replacement. Please share your knowledge and experiences.