Housekeeping big tables, need ideas/advices

I have a rather large tables with many columns 90mil rows with 100columns.

Lately the users are complaining that the performance for this table is very slow when they're doing a FTS query. The table does have indexes on certain columns thus no issue when indexes are use in the query. However certain times the developers will do a simple select all statement which will invoke a FTS, this will take very long time to produce any result.

I have suggested them to have that table housekept because it's keeping data up to 10 years. My idea idea is to pull out maybe 5 years worth of data into an archive table then delete it from the main table. This would reduce the FTS time on the main table. The downside of this is doing that much of insert will be significantly slow due to the number of rows & column involve.