I’m not that familiar with the topic but on a quick reading I would say that the Encyclical is a bit confusing.
The original meaning of the word “eros” was “lust”.
But the Pope is using the term to mean “marital love”.
Obviously, the encyclical cannot be praising lust – although it does seem that way when using the word “eros” and that word is not defined in the text of the encyclical.
I think this teaching is merely pointing out that marital love is a blessing from God. It cannot be an end in itself.
This was written against the notion that Catholic doctrine teaches a hatred for marriage and the joys that God has given to that state.
But I will admit that it could appear like the Pope was talking about lust itself, detached from marriage, or even in marriage – as if that form of self-indulgence was something good.
This encyclical must be read together with the many teachings of the Church on the dangers of the passions of man – especially lust which has many forms (gluttony, greed, flesh, sensuality).