In the Reports -> Strength Training you can see a report including number of reps and volume which could be a good way to monitor your progress in each exercise. But the thing is that when we select granularity greater than 7 days days data is aggregated by week in case of last 4 weeks and by month in options 6 months and 1 year.
The aggregation makes the feature completely useless - aggregated data means nothing - there are different numbers of trainings in each months because of their length and 1st days of month differences. For example when you do your workout every Mon, Wed and Fri there are completely different numbers of workouts per each month.
I can not really understand what is the value of report showing that you have worse values on the chart in February than in January because of Feb is shorter.