Some may say, that:

“It is difficult to apply the laws of Manu in today’s world since the conditions that exist now are very different from those when they were formally codified.”

But it’s not really true – even if some laws we may not be able to apply, due to current law system – still there are plenty of principal laws, which we can definitely apply. In Bhagavad Gita is said, that better to imperfectly do what is your duty than perfectly what is not. The same is said in Manu Samhita itself – even if you are imperfect and conditions imperfect, better is to do what is your dharma and duties.

Also – Applicability of Laws of Manu in modern age depends very much on interpretation of Manu smrti. If you will take verses of MS out of context, by your own ignorant interpretation, in a wrong way – then I doubt that such “laws of Manu” must be applied at all. But if you will follow right path – weighing everything in a sense of knowledge presented through authoritative school of thought and sampradaya – then there must not be any problem at all.

About women

Some may say:

“For example, our current laws do not permit gender bias or the imposition of restrictive law upon women or their freedom to choose their marriage partners, their profession or their ways of life.“

First of all, it’s not gender bias. It’s description of Nature. Second – Manu Samhita by itself says that not by force, but by free will. I clearly doubt that Democratic society and current law system will have any problem with girls and women who would want to follow path of a chaste woman and accept duties described in Manu Samhita. Problem could start when other women and feminists would read that they live like prostitutes, and feel offended – but then this is unacceptable bias by itself from their side – why they think that prostitute is something bad? Or porn star? If they are so concerned about democratic values – for example if white man is offended, because he is called black man – then he is a racist. Why he thinks that black is something bad? Do you get it?

Anyway – I do not see absolutely no problem, for women, especially for devotee women to accept by free will path of a chastity described in Manu Samhita and Srimad Bhagavatam. If they want to live in prostitution – that’s their choice. In history there are many examples of highly advanced Krishna Bhaktas prostitutes.

About casteism

Some may say:

“Similarly, the laws governing the conduct of people according to their caste or occupation are discriminatory by today’s standards and cannot be enforced.”

As I said – discriminatory are certain interpretations of varnasrama system.
Not only discriminative – but also degradative – and again – who said that they must be enforced? Manu Samhita gives many examples how to live in times of distress, how to act in times of emergency. Besides that – there is certain understanding about primary and secondary laws, duties and principles.
There are duties meant for all the varnas – and they are the same to everyone, applicable not by force, but by free will. Let’s focus on them in these times of distress.

There are no problems and limitations in Manu Samhita. It’s only in our heads.
Manusmriti is not some historical work, thing of a past. It’s eternal laws, laws of nature. It must be studied not for “to understand the way of life in ancient India and how people governed their lives with its help”. It must be studied for to implement it now, in our ordinary lives – because it HELPS – to live as humans. But according Srila Prabhupada – only in human society we can talk about understanding of God.