The lowest the European HY option-adjusted spreads went before was approx 1.8%, vs 2.48% now.
In the US the option adjustedspread is about 3.5%, the lowest it got in the last 20 years is about 2.4%. The lowest nominal yields got was about 5.2% in 2014 vs 5.5% now as the Fed continues hiking.
However, in Q2 2007 HY yields were over 6% vs 2 and change now. Nominal yields are higher in the US but the Fed is also hiking, the US is further ahead in the cycle and defaults should rise sooner in the US than EU.
To put it into perspective long run default rates could average 2-3% and can spike into the teens in the aftermath of a recession.
There is also nothing there for risk emanating from the political economy, of which there is plenty in dysfunctional Europe.
Truthfully if nothing much happens then technicals could tighten spreads to record lows, but that is just a game of picking up pennies infront of a freight train.