Remember, nothing is alleged to--or can have--happened to all of MLB over some one or two seasons: the claim is that PEDs were being used at a slowly but steadily increasing rate (and thus "distorting records") from very roughly 1980 through the present. Were that so, or anything like it, we would expect to see a clear long-term uptrend during this period. But we don't: we see a nearly flat line that, if anything, slopes slightly down. The "boost" just isn't there. But that doesn't seem to stop anyone from talking about it.
There are many, many different steroids.
Anabolic steroids are the ones that can get abused by athletes.
Corticosteroids are the ones used to treat inflammation.
Long term use of steroids can be a problem but when it's used to treat an inflammation, it's very short term.
I don't get poison ivy often but when I do the reaction will not shut down on it's own (my record for scratching was just over 2 months) and a Prednzone series (steroid) is the only thing that stops it.
When my son was 3, he was on the same thing for 2 weeks to try to shrink his tonsils (worked while he was taking it, but they blew back up when we finished, so we had them out).
Not being able to breathe is way worse than the little dose of steroid that is used to help clear it up.