It is everything it has always been.
Sex without tantra is bliss and excitement.
Many people will have tantric like experiences and never call it tantra.
Millions of people on this planet practice sex and find it very fulfilling in itself.
They can gain great satisfaction and have children as well.
The way your instinctual sexual nature was created is perfect in itself.
Now, when you practice sex within a tantric context, you might touch on levels of awareness and pleasure you did not discover before.
The reason this happens is because you are surrounded by a sponsoring force or energy which encourages a very specific set of emotions, feelings, impressions and energy flow.
Sex without tantra might simply miss this mystical or absolute dimension.
You might as well miss the full pleasure experience of sex.
However, these experiences do not belong to tantra only. They are simply enhanced and facilitated within the tantric mind set.