By Rupert Hargreaves Advertising group S4Capital has reported a decline in revenue and operating profit as “challenging macroeconomic conditions” took their toll on the group in 2023. The company, founded by advertising giant Sir Martin Sorrell, was established to try and replicate the success of his former company WPP. S4 has aggressively purchased a series of companies over the past few years with the aim of establishing a digital-focused rival to its larger, more established peer. However, the group appears to have hit a stumbling block. While its 2023 results were in line with expectations…