The barrister/solicitor split is theoretically that between litigation (solicitor) and advocacy (barrister). If you're a commercial solicitor working in the city it's very much not a second-best option and is very lucrative. Solicitors do advocacy in the lower courts, but it's theoretically not the main focus of their job.
You're right that it's generally harder to fully qualify as a barrister, though [edit: in England and Wales]: there's a compulsory year-long practical training in a law firm element, which is murderous to try to get a spot in.
The distinction's actually eroding in the UK. Solicitors can train in advocacy and get rights of audience in the higher courts, and barristers can now be instructed directly by the public (which used to be illegal: their client was always a solicitor).
Litigation is not the right word for solicitors' work in general – they do a lot of non-contentious business, especially in the City (eg. corporate finance and M&A). Although many solicitors do litigation (which includes advocacy in the courts), most barristers do it exclusively. Also, it is solicitors who are required to undertake a year of practical training in a law firm [1]. Barristers do a pupillage [2] under the supervision of a mentor.
"Solicitors can train in advocacy and get rights of audience in the higher courts"
Solicitors who do get the right of audience apparently don't appear as much as you'd expect - solicitors still use barristers/advocates to offload risk on high value cases.
You're right that it's generally harder to fully qualify as a barrister, though [edit: in England and Wales]: there's a compulsory year-long practical training in a law firm element, which is murderous to try to get a spot in.
The distinction's actually eroding in the UK. Solicitors can train in advocacy and get rights of audience in the higher courts, and barristers can now be instructed directly by the public (which used to be illegal: their client was always a solicitor).