hariḥ oṁ
~~~~~~
namasté

You are not wrong about samadhi, as samadhi means union and when union is attained liberation from birth and death is also attained.
Let's look to what rāmaṇa maharṣi says.

Q: What is mokṣa ?
A: Mokṣa is to know that you were never born 1.

This is confirmed in the bhāgavad gītā ( chapter 2 called sāṅkhyayoga, 12th verse)
natvevāhaṁ jātu nāsaṁ na tvaṁneme janādhipāḥ|
na caiva na bhaviṣyāmaḥ sarve vayamataḥ param||12

this says,
there never was a time when I was not ( kṛṣṇaḥ is speaking to arguna) nor you, nor these
rulers amongst men; nor will there ever come a time when we all cease to be ||

So, when rāmaṇa maharṣi says 'mokṣa is to know you were never born' , it is to realize the truth of this 12th verse offered by kṛṣṇaḥ.
Yet if your frame of reference stays within the notion that 'I' am this person called yajvan, or bill, or sue, or tim, and this person as an individual has a beginning middle and end, that it is a bundle of flesh, nerves and organs that only wakes, dreams and sleeps, then it will be difficult to grasp the notion of never being born ( and never ceasing to be). For this to have the highest appreciation one needs to be acquainted with Being/pure awareness, that is boundless.

iti śivaṁ

1. From 'Talks With Rāmaṇa Maharṣi' 6th of January 1936