Paid sick leave was not the primary issue. The primary issue that the unions were striking about is "precision rail scheduling" which basically has rail workers on a 24/7 on call. They have no time off, and failing to answer a midnight or 4 am call to go to a train and drive it costs you your job. One of the reasons workers wouldn't answer a call was because they were sick, and had no sick days.

So, the main issue has not been resolved and the strike was broken before it even started, and this sick day thing is just a small concession that Biden got the rail companies to give

He did get the rail workers sick days but that wasn't the only thing they were striking for. Rail workers went from 0 to 8 sick days per year (they don't carry over if unused) which is paltry and ignores some of the other many problems with the rail industry.

#1 Work:Life ratio: the average rail worker is on what is known as the extra board where all the non-scheduled trains go. This system effectively makes them on-call but doesn't give the pay on-call should give due to problem number 2.

#2: Poor (or non) scheduling: The US Railroad companies like to tout "Precision Scheduled Railroading," their system that allegedly allows for more precise schedules. To quote a podcast thats popular here, "its neither precision, nor scheduled, nor railroading." Train companies create schedules that they can't keep with trains twice the length of what one train can handle but 3 can mostly do it without blowing up a small town (with one crew controlling all three of them), and then put all the late trains from the previous scheduling problems on the extra board. Then as a bonus they can reprimand crews for not making the impossible timetable. This is a process that is currently eating crews and is still getting worse.

#3 Non-investment: you cannot buy a new overhead electric rail freight locomotive in America, even if you wanted to you can only buy battery ones which are less efficient than diesel (when you consider America's power supply, natural gas). Rail yards for sorting cars are only designed to handle the old 70ish car length trains instead of the current 150 monster train configurations and some of them are expensive to make bigger, some of them are literally impossible to make bigger because of the stuff around them. There has been virtually no investments in rail infrastructure so Amtrack trains are still sharing tracks with these random monster trains, forcing the Amtrack trains onto sidings to wait while they pass despite congressional mandates against that because the monster trains don't fit in the sidings anymore. This problem is deep and short of complete nationalisation will not be solved because being this cheap is profitable.

Additional listening: Work Stoppage on the Rail Strike and the Labour angle from the time, Well There's Your Problem: American Rail Freight.

Another fun detail is that the workers getting the sick leave are not the same workers that were threatening to strike.

https://ble-t.org/news/railroads-taking-tougher-stance-on-paid-sick-leave-for-blet/