From my read of the Manifesto… while I may not have been impressed by the writing, that is from my perspective over 150 years later.
We got a lot of the things Marx was calling for. Of the 10 point plan near the end of section 2, we got:
- "2. A heavy progressive or graduated income tax." today's rates look "heavy" by the standards of the 1848, even if we've also seen it decline somewhat from the peak.
- "3. Abolition of all rights of inheritance." not fully of course, but inheritance tax is absolutely a thing in a way it wasn't in 1848, and was one of the contributors to the decline of country estates in the UK.
- "5. Centralisation of credit in the hands of the state, by means of a national bank with State capital and an exclusive monopoly.", again, clearly not as described, but the central banks do now direct how much credit costs for all the other banks, and financial regulation has changed hugely since then (even if some of this has also been falling away as quickly as the rich think they can get away with it).
- "6. Centralisation of the means of communication and transport in the hands of the State." has been on-and-off in the intervening time depending on where and which technology: the Royal Mail/USPS; I'm not quite old enough to remember the end of British Telecoms' monopoly on UK phones. For transport, likewise, depends on the specifics, does the British Highways Agency or American Federal Highway Administration count? Motor vehicles (let alone aircraft) came quite some time after the Manifesto was written, the tech of that era was shipping and canals, railways existed but the big boom hadn't happened yet. British Rail was a nationalised thing when I was young. Deutsche Bahn is still state-owned, but on the other hand British busses are private and I don't know how to think correctly about how British bus routes are run/bid for/regulated.
- "7. …; the bringing into cultivation of waste-lands, and the improvement of the soil generally in accordance with a common plan." (trimmed a bit I'm not sure about), Superfund site cleanup?
- "9. Combination of agriculture with manufacturing industries; …" (trimmed the absolutely-not part), this seems correct, given how industrialised farming is?
- "10. Free education for all children in public schools. Abolition of
children’s factory labour in its present form. Combination of education
with industrial production, &c, &c." - done so hard we don't even want to trade with places that don't do it
Remember, the form of capitalism that Marx et al were fighting against was laissez-faire, which basically died with the Great Depression. It's not the form of mixed economics we have today which we still call "capitalism".