I have two family members who recently had Covid. One had multiple comorbidities. She gets the flu & pneumonia at least once a year. I was terrified for her. Her symptoms were mostly a horrible headache for a week & weakness. Her PCP called in meds for her & told her to go to the emergency room, if she got worse. She never had to go to the hospital. I'm thinking she probably received a low viral load, because no one else in her immediate family tested positive. They had all shared a house on vacation, prior to her testing positive. The second, a 35 year old nurse, was admitted to the hospital two days after she tested positive. The next day she was sent to ICU. Fortunately, they didn't have to put her on a ventilator, but she's still on oxygen, even though she's been released from the hospital.
Some of you have probably heard about the 19 year old that was perfectly healthy, yet passed away last week. He attended to the same college my niece & nephew attended for undergrad. That was a heartbreaking story.
So, no, I don't think it's getting weaker. Like JimMIA mentioned, I do think they're getting better at treating it, if they catch it early enough.