Skiplagging, particularly on a carrier you have no relationship with can also make for cheap premium seats.
Let’s say I wanted to get to FRA and Lufthansa has J seats for $2,500 RT direct, but if I can live with just overhead baggage I could instead book two one way segments that end elsewhere for…half the price? Done.
Example: DFW-FRA-TLV and skip the TLV segment and FRA-DFW-ABQ on the return and skip the ABQ segment.
Skiplagging too often with the same carrier is a good way to get yourself blacklisted from flying them at all for a period of time. And, as you noted, not an airline you have a relationship with (status, miles you care about etc.)
And be careful skiplagging with TLV as a destination if you actually want to go there someday. Great way to get flagged by Israeli security…